At my parents', they have an outdoor kiddie pool. I got one here for the really hot days, but my crew is uninterested.
If you want something smaller indoors, you might try a plastic storage container. You could even nest it in a larger one for some of the splash/spill.
If you want something smaller indoors, you might try a plastic storage container. You could even nest it in a larger one for some of the splash/spill.