Protip; make sure to check the material is genuinely safe. Stainless steel, Glass and Platinum Silicone are about the only ones you want to get intimately involved with.
A lot of toys these days are made out of unsafe silicones (anything plastic or flexible that isn't made from platinum cure silicone will leech toxic chemicals over time) TPE, PVC, 'jelly rubber' and a number of other plastics. Because of the way they're made, these materials are porous, so will build up pockets of bacteria that can't be cleaned off with boiling or bleaching, simply because they break apart under high temperature or chemicals.
Short and sweet of it is that by spending a little more to get something that's worth it, you won't be putting your health at risk (also treat yourself, because nobody deserves a bad toy)
Strontium Aluminate powder (for when you want a clear paint or lacquer to glow for HOURS, wear gloves though, it's like glitter if you spill any)
Also try Dosidos and Wedding Cake :D