Thermal Scarf

Has anyone heard of using a thermal scarf while observing. No, this isn't a personal (usually female) article of clothing. It's made of a cork type of material and you supposedly wrap if around the circumferance of your mirror. Since the edge of the mirror cools faster than the center it is supposed to keep the edge and center closer to proper optical properties during the cooling process.

Heard of it. It's old school and I believe properly for plate glass? Pyrex and active cooling may have somewhat out-moded it. Having said that, I plan to try it on my 13" because it is plate and it would be a pretty inexpencive experiment.