Try a pharmacy. Speak to a pharmacist rather than the regular help. Glycerin is also an unwanted byproduct in the manufacture of biodiesel from vegetable oil. If you find somebody cooking up biodiesel in his basement, you will be offered several hundred gallons of the stuff.
--
Michael Shiffer
EuroMeccanica, Inc.
114 Pearl Street
Mount Vernon, NY 10550
(914) 668-1300
euromeccanicany.com