This is a dumb question, but I don't want to screw something up, so I figured I'd ask anyway. I know most places recommend terracotta or ceramic pots for cacti, and plastic is fine, but what about metal?

For example, I have about a dozen old tea tins (not sure if they're actually tin). If I punched a couple good-sized holes for drainage and used a decent soil/sand/perlite mixture, would that work just as well? Or might chemicals/minerals leech out of the metal that could damage my cacti?

It'd be nice if I could use these tins for something. I guess I could fill the bottoms with gravel and just set plastic pots inside or something.