Right or wrong, I don’t apply heat until after hanging begins. The reasons are 1) I don’t believe heat is as critical when hanging as opposed to jelqing. 2) Heat while wrapped w/o hanger tends to makes the glans fill up with blood, whichs leads to high pressure/discomfort while hanging. (thus I don’t use heat between sets anymore)
I use a rice “bag” rather than a sock. My sweet wife made it by sewing two square washcloths together and partially filling with 2 lbs of rice. It nicely lays over the whole hanging “system”.
Although now I mainly hang BTC which is makes it hard to type this message while using one hand to hold the bag against Mr. Wille.