The third approach has a lot in common with the second. It's also inclined to make the concept of "canon" incredibly wobbly, if not actually non-existent. It doesn't feel that party loyalty requires it to pretend that Doctor Who was good even when it quite obviously wasn't. It takes the line that the story on the back of the Nestles Chocolate Bars is as much a part of Doctor Who as anything which ever appeared on TV -- or that it can be if you want it to be.
But while it is certainly interested in ephemera and memorabilia, it isn't that interested in putting Doctor Who in a particular historical or biographical context. You can read whole articles written from this perspective without finding out how old the writer was when they first saw Genesis of the Daleks, or how much they disliked their P.E teacher. It regards Doctor Who as a text -- but it thinks that that text is potentially very large and (therefore) very contradictory. What you do with the text is "read" it, appreciate it, and, if you wish, interpret it. The Third Approach is interested in seeing how the Lyons Maid Dalek Death Ray Lolly wrappers fit into, or can be fitted into, the Total Text of Doctor Who: it is not particularly interested in how you felt when you first discovered them in the freezer cabinet in the long drought of 1976. The Daleks were created by a crippled fascist called Davros and also by a smurf named Yarvelling : that contradiction is a fact about the text, in the same way that "it used to be in black and white and then it went to colour" are facts about it. What you do with it is up to you. But you shouldn't (according to this theory) use the concept of canon to privilege one over the other or to falsify a unity and consistency which simply isn't there.
The Second Approach asked "What does Doctor Who mean to me?" The Third one asks "What does Doctor Who mean?"
This is of course the furrow that Andrew Hickey is plowing so cleverly, both in his Mindless Ones columns and his own blog. They are are full of interesting -- if highly tendentious -- ways of reading the actual text of Doctor Who. In his inspired riff on Logopolis he notes that Adric -- greedy for food, awkward around girls, obsessed with maths and computers, far too pleased with himself -- could have been a deliberate parody of a Doctor Who fan, and is, not un-coincidentally, the character Doctor Who fans most universally hate. That never occurred when I first saw the Adric stories; it hadn't occurred to me in the thirty years since; I very much doubt that it was consciously in John Nathan-Turner's mind when he dreamed up Adric; but now the observation has been made, it can't be un-made. It is obviously, compellingly true.
But this approach also has a drawbridge. "Textual interpretation" is arguably quite a strange thing to be doing to what is, when all is said and done, a children's TV adventure serial. When we wonder if "The Watcher" who is watching the Doctor in Logopolis might possibly represent us, the person who is watching the Doctor on the TV (which would mean that we, the viewers, were really the Doctor all the time) we are doing something to Doctor Who which it would never have occurred to us to do to Doctor Who if we had not already put Doctor Who up on the kind of pedestal where that's the kind of thing that it occurs to us to do to it.
And that's what "canonization" means, isn't it? Putting a book, or a person, on a pedestal? It originally referred to the canon of Holy Scripture.  No-one would argue about whether the book of Maccabees was, or was not, Scripture if they didn't already think that there was such a thing as Scripture for it to be -- a special kind of book that you treat in a special kind of way. We may admire the Screwtape Letters very much -- more than we admire the Epistle to Jude, if we are perfectly honest. But we don't think that it would be appropriate to pick a particular sentence from Screwtape as Collect of the Day or use it as the starting point of a sermon or set it to music or use it liturgically or swing censers of incense in front of. Neither do we, on the whole, write articles about the internal continuity of Rentaghost. Even though we loved Rentaghost at exactly the same moment we first loved Doctor Who.
Some clergymen treat the Bible as (at best) as a collection of raw material to do exegeses of; and at worst, a convenient source of sermon illustrations. Some academics regard novels primarily as things to fall out with other academics over. And if we aren't careful, the whole process of "being Doctor Who fans" can make Doctor Who, the television programme invisible.
Almost the most interesting thing about Andrew's "Fifty Stories for Fifty Years" series is the way he treated The Iron Legion  and Doctor Who and the Cave Monsters  as part of the Total Thing Which Is Doctor Who. But by opening up the canon in this way, he is acknowledging that there is such a thing as canonicity. He reads The Iron Legion in a way in which it would not occur to us to read Beryl the Peril or Winker Watson .
"What if everything is canonical?" is a perfectly good question. But it's a slightly different question to "What if nothing is?"
What if the stories on the backs of the Sugar Puffs packets are just as much a part of the Doctor Who canon as the Dalek Masterplan?
What if doing a close analysis of a forty-seven year old television programme (of which no copies exist) is just as silly as doing a close analysis of the backs of old cereal boxes?
 In the TV Century 21 Comic Strip...but you knew that.
 I think that an explanation along the lines of: "They both happened, but in alternate time lines" is just as much a smoothing over as "Davros rediscovered Yarvelling's long lost blueprints" or "TV Century 21 is NOT CANON and DOESN'T COUNT." My preferred answer (to get ahead of myself) is "It doesn't matter that they contradict each other, because neither of them 'really happened': they are both stories."
 Andrew Hickey has helpfully reminded us that we owe the word's application to popular culture to a spoof article in which a clergyman applied the methods of Historical Jesus Scholarship and source criticism to the Sherlock Holmes stories.
 A comic strip in "Doctor Who Weekly". You knew that as well.
 The novelisation of "The Silurians".
 Comic strips in the Beano.