from what i read they typically use propylene glycol with these correct. Im no chemist but i was under the assumption that you could extract the thc and cannabinoids with ethanol first then mix with the propylene glycol or glycerin, and alcohol having the lower boiling point you could boil out the alcohol and be left with the goodies in the probylene glycol and then dip the filter papers into that, to then replace, thus the same thing, but less i dunno, chemically? just a thought though, it has come up after a buddy got one and we were wondering, ill have to let them know about this though.