i have yet to find an awnser to my question. i cant seem to find teflon stoppers, is it ok to use a dry spray stick on teflon on a rubber cork? and back to my original question, is it ok to distill dcm using a rubber or cork stopper, i cant find any info that says i can not. The thread concerning cork said not to store the gbl in a bottle with a cork stopper for extended periods, is it ok to use cork on a distilation apparatus with out terribly hurting th purity of the gbl? thanks