Chiming in from Athens, Greece, where hemp is still commonly in use in plumbing. Existing fitting is a flare nut captive on copper pipe. Prior installer had used several layers of hemp to pack around behind the flare. The effect is sort of like having a felt washer between the flare nut and the inlet nipple. The hemp seems to be impregnated with some kind of cream or wax. Anyone have any idea what this substance is?