I didn't see it end - did BJ finally "get" Hawkeye?

Yes, and no.

See, the joke was that BJ played a joke on Hawkeye by not playing a joke on him.

All the others were in on the scheme, and everyone played a joke on themselves (the snake in Charles' bed, Klinger's exploding file cabinet, etc) making Hawkeye think that BJ had "got" them too.

Hawkeye became extremly paranoid that he was going to be next, and he was wating for the practical joke that would never come.

And that was the joke.

then Hawk had to stand on a table in the mess tent and do a striptease while singing "You're the top".:lol:
That was 1 episode of "The Alan Alda show"-oops, I mean the later episodes-that I liked.

That was a funny episode.