Glycerin at trace... that sounds very do-able. I have a large jug as I use it when I make liquid soap - don't usually add to my CP because it's already a natural byproduct. Someone recently told me adding sugar helps to stabalize the bubble as well. Any type of sugar - honey, beer, regular...
Within the last year I have added shaving soap to my line - it's wonderful soap, I use it daily. I have had a few shave-guru's (guys who are totally into the handmade shaving soaps, mugs, and brushes big-time... and have used many kinds) let me know my soap is wonderful for the skin but doesn't...