I know that it's essential to have position on a maniac, both at the table and in a hand. Even with position, I still get torn to pieces by maniacs in 6-max PLO hi. When I see stats like 60/40/5 with a 60% aggression frequency (3.5 aggression factor), I have a very hard time respecting their bets on the flop and turn. I know about Caffione's concept that calling a maniac's first bet puts you into Triple Jeopardy: you can lose if they are not bluffing, you can lose if they improve, and you can lose if you get bluffed out on a later street. Even so, I feel like I'm still missing a key concept or two.
Suppose you flop second nut flush and the maniac who was the PFR (as he is 40% of the time) just continuation bet full pot (as he does 80% of the time.) What the hell do you do? The maniac always has the nut flush in this spot, in my experience. I know second nut flush is not a good hand in Omaha, but I feel like I'm missing the concept that will let me auto-fold it versus a maniac's bet.
One concept I use in Hold'em versus a maniac is I ask myself if I can beat a random hand. If not, I fold.
One thing I've realized is that if a maniac check-raises you when the flop comes 752 or similar, you can lay down AAxx without a second thought. The thing is, it's easy for the loose maniac to have a set. He'll play any hand with any pair in it. Therefore, the low flops belong to the loose maniac. Hmm, this might be the secret to the semi-success of Omaha maniacs - by spewing pot sized bets left and right with weak hands, a maniac lures his opponents into getting stacked by his stronger hands, like bottom set. We, on the other hand, get very little value when we hold bottom set.
Any other useful concepts?