Here are a few: glass baking dish ... the clear glass containers you find that set on one side and have a lid (look similar to a fish bowl with an extra flat side ...
... a chimnenia ... clay pots ... ceramic pots ... if you have somewhere you can get lots of small cardboard boxes - those would even be disposable ... there is one that is ceramic that looks like a chinchilla that works great ... an empty cardboard oatmeal container ... a wooden or metal tray. The best ones (for the least mess) will usually have tall sides and or a small opening (less gets flung into the air with these).
Avoid thin glass, aluminum and plastic containers.
Only allow the bath to last 15 to 20 minutes max.
Hope this helped.
Jo Ann