HCA: Hermit Crab Association

I'm browsing the internet for good places to buy shells that aren't too expensive. A lot of the shells are polished.. is this okay or is this similar to the issue of painted shells?

Polished shells should be just fine!

Polishing shells is just smoothing down the shell, it isn't a chemical polish. So yes it is safe. I have a couple polishes shells, mostly green turbos...my crabs aren't interested in them though.