How do you clean an old Stem?

So I was talking with the owner of my local tobacco shop and mentioned that I have a briar block and was going to try to make my own pipe but was wondering if he sold stems or new a local place to get one. He handed me an old stem off a pipe that was burnt out saying that I could have it, but it was gonna need cleaned. it looked like the thing was full of cake! its a bent stem so running a drill through it wont work,....

So any advise. other than just buy a new one? I know buying one is fairly cheap and simple, but hey, I like doing things the hard way!

Yep, I second that bristle cleaner trick. You could leave it soaked in alcohol for a while. Just keep an eye on it if you do. Some material gets weak when sitting for too long in alcohol. - at leas that's what happened to me once. The stem felt like rubber when I took it out. So, now I don't leave any stem in longer than a couple of hours.

Its a Lucite stem, probably should have stated that in the first post... My Bad. I had it soaking in a small jar of everclear while I posted just to see if that would work. now here it is a couple hours later and thanks to my pokey thingy on my pipe tool and about 3 dozen pipe cleaners it is nice and clean. Thanks guys.