making gauges?

[hopesicle.livejournal.com]

So I want to make my friend a pair of plugs and am wondering if anyone has any tutorials? I was thinking of just buying some flesh tunnels and using resin kind of like this http://www.mega-robot.com/collections/plugs-gauges/products/photo-image-bear-plugs. Thoughts? Other ideas/techniques? I've never actually worked with resin, but I think it would be a fun thing to learn. I also had the thought of making some out of fimo or other clay, but I'm wondering if that would be toxic to put in one's ears. Any and all advice welcome. I'll be sure to post whatever I make!