Actually they make a wrap which is sort of like cloth, but is made for high temperature applications.

I know it only as "header wrap". Just go to an automotive store or a race shop and I'm sure you could find it. Summit Racing might even have the stuff.

Racers use it for cars when a header gets too hot and they have to protect other parts inside the engine compartment from heat.

I can't imagine the stuff is too expensive, and barring any issues it might cause with keeping your motor/pipe too hot, I'm sure it would knock down the heat pretty well....and wouldn't be that goofy looking reflective tape crap...

Hope that helps...