[?] It is probably not heat that melted the rubber. It?s likely degradation. Some rubber parts get dry and break, some parts sort of ?melt? and turn into this sticky, nasty glue. You already got some hints on how to clean this, but if you are nervous, you could start off with just isopropanol (that?s the main ingredient in disinfectant). The advantage here would be that you can?t harm plastic or electronics with that. You could use the common medical grade disinfectant, just don?t drink it ;-) Dennis