As an alternative medicine/new age wellness woo moneymaker, any product at all that's labelled "colloidal semiconductor quantum dots" would clean up. (I'm thinking little colourful stickers, perhaps with a bit of glitter in a varnish suspension.)
I decided when I heard about the maple water fad that if I ever Break Bad, I'm going to sell snake oil patent medicines to the Whole Foods crowd. Walking down their alternative medicine section was… inspirational. I especially liked the colloidal silver[1].