I use 99% Isopropyl Alcohol. i soak the bowl.. then rinse with hot water repeatedly... i can get my glass bong looking like brand new.. not that you always Want to.. but it comes in handy for those times when you can't pull through your bong because of the mass buildup of resin
Hey man... you shouldnt smoke out of anything not fired in a kiln, I'd go so far as to say fired as well as glazed with a dishware safe glaze....there is a clay shop by my house, nothing but clays, and the guy that runs it knew we wanted to make pipes and told us all we needed to know... so yeah... self hardening prolly isnt that safe... by the way... glazing is actually glass so you know thats safe.... plus... a nice glaze is very attractive... would be nice to have an artistic home made piece
You might be right, though I can't imagine what would be unsafe about it. The thing is, I don't have a kiln, but I do have a block of self hardening clay. So there's not much of a choice to be made, lol.
My brother made a clay pipe once and let it harden under the sunlight. I think it worked fine but I never actually used it.