I used vodka mixed with the shimmer dust last week to paint a bow but it left the surface a bit streaky and tacky (like it never fully dried).

Is there something else I could use that would dry completely?

I like using everclear instead of vodka.

If you're using Wilton shimmer dust to paint, please just give up.

It just won't work. The pigments are too granular and I suspect that there is too much cornstarch in them. They can be used for some dry dusting, but that's about it.

You really need decent luster dust or, better yet, Crystal Colors FDA approved (sugarpaste.com) pearl series dusts to get a nice painted finish. Vodka mixed with those should dry just fine. Using a good lemon extract can also help decrease streaks.

HTH
Rae