My only experience was at DP but they don't empty the pool of water if that's what you mean.
They set up the foam machine on one end of the pool and it blows inland and sits on top of the water. It only covers one end of the pool so you are not trapped. The foam is pretty slippery but you are standing in the pool water so you're not going to slip on the foam - your hands will just slip all over your wife's body. The naked people are naked, the people with swim suits on will probably take them off when they see all the naked people having fun! Seriously, you can be ask naked as you want to be - just like all the other times.
The foam does get pretty high and potentially claustrophobic if you are inclined to that kind of thing. If that's an issue, you just keep to the side a bit and move out of the main flow. It builds relatively slowly so it's not like you are just thrown into a vat of foam. You can hang in the fringes of the foam and regulate how closed in you can tolerate. It's really not a big deal and you can easily manage how immersed you are in it. Like a lot of things at Desire, it's probably best not to over-think it. I know it's tough when you don't know what to expect but you are in full control. Don't worry - be sexy!