CTers can change the rules whenever they see fit and then go cry to mama Dylan. So it wouldn't do any good.
Perhaps. Still, it would be interesting to see if any CTist would be willing to engage in an argument on that basis. It would, at least, be a way of more rapidly exposing those who, like Killtown, have no serious interest in exploring and weighing evidence.
You'll note, too, that I'm not suggesting that the claimant would have to agree to any "rules." If those skeptical of the claimant's position simply agreed among themselves that they would not address anything the claimant had to say until that claimant had acknowledged that some mutually agreed upon step in the argument had been settled ("mutually" here meaning "among those skeptical of the claim") one way or the other, then attempts by the claimant to "break the rules" simply wouldn't matter.
This thread in particular seems to cry out for some such approach simply because Killtown is so clearly frivolous in his arguments. At some level he clearly doesn't really "believe" any part of them; that is, he's just as happy to hold that the photo is photoshopped as he is to hold that it's a genuine photo of "ordnance" which debunks the OV, despite the fact that these two propositions are mutually incompatible. As long as there's something "fishy" and as long as it feeds his sense of self-importance ("I know something THEY don't want me to know") he's happy.
There'd be some value in refusing to feed that sense of self-importance by getting him to the "put up or shut up" point a great deal more rapidly.