I found this on the net .......
A homemade poultice an be produced using Dry porcelain clay mixed to a peanut-butter consistency with equal parts of water and glycerin. Small quantities of glycerin are available at most pharmacies; for larger quantities, search the Internet for soap-making supplies, floral supplies, etc. or check your Yellow Pages for "soapmaking supplies"; the large craft stores might carry it as well (Michaels, Hobby Lobby, etc.) Just be sure to stay away from "glycerin melt-and-pour" soap base. You'll need straight glycerin (you'll mostly likely find "vegetable" glycerin). Please be sure NOT to ask for NITRO-GLYCERIN. You will have every law enforcement agency in the country checking your personal history and watching your every move.