If you used reusable swim diapers (like iPlay), did you put a swimsuit over it? Or did you use the bottoms as swimsuit bottoms and just throw on a rash guard? Or did they just swim in the diaper and nothing else?

Just found out the house we are renting this weekend for a getaway with our friends has access to an indoor, heated pool. I've been wanting to start my LOs in swim lessons and thought this would be a good time to try out a pool before we pay for lessons. But now I have to quickly figure out swim gear. Would you even bother with a swimsuit at all if they were going to be in an indoor, heated pool? (Admittedly I think putting them in swimsuits would be really cute, but if it's totally unnecessary, I wouldn't mind skipping them to save money on a swimsuit they won't wear much!)