Not in a pool with chemicals.. That is a big NO NO..
I use a small blow-up pool with reg hose water.. Again this is my 14'+ burm. Not my ball pythons.. If you put your snake in a pool like a bp it would swim for a bit I bet then sink and drown.. This would be bad.
My burm can just fit in the pool and is used to being in water..
Sorry didnt want to confuse.