If you'll look at the pics I have of my pot, you'll see that I have used some yellow stuff to insulate it with and this is what I used.
http://www.vanaken.com/plastalina.html
Got it from Hobby Lobby in 1lb bricks and so far it's done really well. Easy to spread around/work with, it has a sticky texture/sticks well to wherever you apply it, doesn't harden and water doesn't seem to affect it either. Best of all after doing a run I simply peel it off, wad it into a "Ball" and I can reuse it later.
Went ahead and got me a few bricks to have onhand so I'll have enough to last for sometime. I don't know if any of you have ever tried it but so far I've had good luck with it. Also with it being reuseable it's cost effective so a couple of bricks properly used should last awhile. I've been using 2 1lb bricks of the stuff with my setup so I know at least 3 should be enough for just about anything. Just be sure if you try it to seal it up in a tupperware container or something if not using it because it will attract stuff like pet hair since it is kinda sticky.