If you are not using your normal exposure protection, (wetsuit or dry suit complicate the control issue), then the practice will be less valuable. Also the weight you use in a FW pool will be around 6 lbs less than needed in the ocean if you do wear your normal suit, so keep that in mind.
If the pool is too hot for you to wear the full exposure protection, then you can cheat, wear more lead than you need and practice with carrying a little bigger bubble in your BC. This will somewhat mimic the effects of wearing a suit, will make the whole practice a little more challenging and probably result in your being better able to control buoyancy at the end of your practice session(s). Definitely wear, at a minimum, the hood and gloves that you wear diving, so you can better simulate actual conditions and challenges.
Pretend the pool is bottomless and try to never touch it.