I think like huge heaps of glitter would be bad, because someone IS trying to get clean with the soap. A little pop and shine is great, especially because most of us are addicts and we've moved to making decorative soaps of some kind. I like a tiny sprinkle of glitter, a brush of shimmery mica, mica in the top, and I just about cannot make a clear M&P anymore without putting mica in it to make it glittery! So I guess that counts as a type of glitter--just not glitter-sprinkled-on-top glitter.
Of course it all depends on your soap scheme--I have had people ask for a true non scented, no color soap, and of course glitter would be a no-no on that one. (What a frownie-faced soap to make--but at least it's making soap, yes?)
I've read differing opinions on food additives too, that leave me pretty confused, so I've been pretty much staying away from food additives until I read more. I've read that food additives can up the spoilage of your soap, and I've read that food additives can add properties to your soap. I'm not sure how those properties would survive lye, so again, I'm still researching. I suppose it would depend on how you do it, what food it is, when it's put in there, what purpose, etc, and would open up a whole other can of worms.
I do use candy sprinkles and a sugar recipe for my bath bomb cupcake frosting, and a soap frosting combo and bath bomb bottom, but of course those take forever since the soap cures. I use all soap for my soap cupcakes--base and frosting. I like jojoba beads for the decoration those--and glitter!
