If this has been talked about before, please just direct me there.
I have a new to me house with a dozen remodel can lights installed(IC). They of course didn't air seal anything. I was thinking of using terra cotta flower pots with a bit of spray foam to seal them shut. They would let some moisture through, but not a lot, and they would definitely seal each hole. They would be ok with temperatures, being fired clay, and not terribly expensive as well. Am I crazy? Should I stick with taped ridgid insulation, or those $20 fiberboard cups?