Allister soaks in the morning sometimes but its never for a long period of time. When he is shedding however, he soaks a lot, usually for 5 or 6 days at a time.

He has never defecated in his water bowl, or his jaccuzzi hide (where he likes to soak).

Allister defecates and expels urates in the hidebox on the warm side of his terrarium. I just assumed that he likes to pick a spot where he feels most comfortable and pretty much sticks to that. He's funny that way, when he finds something he likes he sticks with it.