I don't know what people think of this play, but what I sometimes do when I end up HU preflop OOP against a very LAG player with a hand like 77 that I know I'm almost always going to show down (unless the board comes down really bad), is I'll cap preflop. I'll only do this if I've noticed my opponent try hopeless bluffs in the past. I figure that, with a medium pocket pair, I'm usually ahead preflop. Since I'm going to calldown against this opponent anyway, I might as well get as much money into the pot as possible while I'm confident I'm ahead of his range.
If I think there's some chance that the preflop cap will stop my opponent from bluffing postflop, I won't try this move, though.
Doing this could also work to my advantage if another player at the table observes this but isn't wise enough to know I'm adjusting to my oppponent. He might take a note on me that 77 is in my preflop capping range, (which it isn't). If I pick up pocket aces against such a player in the future, he won't give me as much respect for it as he should.
So, I don't know, that might be something to try against super-LAGs in the future?
Or maybe trying this makes no sense at all, and I've just wasted everybody's time.