In my opinion, you are playing them correctly. You have to get rid of possible draws. The only time I can see to slow play trips is if the flop is J-6-2 rainbow or something similiar where no flush draw or straight draw seems possible. I have learnt the hard way that slow playing them can be dangerous. I once had AA, the flop came down A-x-x and I checked to the river and then bet big. The other guy hit a straight on the river. Before the turn and river he had nothing so he would have folded to a bet. Similiar situations have happened to me numerous times when I try to slow play trips so now I only do it if I am fairly sure no draws are out there.

If there are 2 suited cards on the flop and someone has another 2 of them in their hole cards, the odds of them hitting a flush by the river are 2-1. So it is wise to tread with caution in my opinion