I have some molded chocolate pieces that I'd like to hand-paint; I've tried the Americolor chocolate colors, and they work well enough, but they never seem to dry.

Do they just take longer to dry because they're oil-based, or does the surface always staya bit tacky and easily rubbed off?

I've had that problem before too. It did finally dry but when touched it does still smear. Wish I knew the answer. Have you tried the pens?

I use luster dusts with confectioner's glaze. It dries 100%.