I think the free samples are long gone. You get free samples if you purchase lbs of fragrance. I really like some of they're oils..BUT the wait time to have them made when I order is a bite in the butt.
Is that the same as the book? The book doesn't cost as much, does it? I think I'd just start with the 12 months access here https://secure.knovel.com/Cart2/knovel/signin.jsp?bookID=599
I don't believe anything can truly foam without the bubbling agent. So there needs to be some type of surfactant in there. I pulled up one recipe that actually did soap with alcohol to make a hand sanitizer. Tie that with some aloe & oils of tea tree & lavender...there you go. You'll still need a high content of water to make it fluid enough for the foamer bottle though. Then a preservative.
Funny, I had that years ago & never knew it was really the heat & the type of wax. Ugly as sin in brown candles. Or wait, maybe that was just the BROWN that was ugly.