How often should I change my bath pouf?

It's best to buy a new one at least once per month.

Should I clean my pouf on a regular basis?

Try cleaning it in an even mix of water and white vinegar. This will disinfect and freshen it without using harsh chemicals that will irritate your skin.

What about storing it between showers?

It's best not to keep your pouf hanging in the shower where it's ripe for the bacteria and mold. Rinse it off well, give it a good shake and hang it outside the shower where it can dry.