I have recently started painting on MMF with Luster Dust and I love the effect it gives.
Currently, I mix it with Lemon Extract and paint it on the fondant. But the lemon extract is expensive and I go through it pretty quickly.
I have heard that people use vodka, but I don't want that taste on the cake.
Could anyone tell me what they use for this?

Vodka doesn't have a taste. The only flavor in the vodka is the alcohol, which disappears as it dries. That's why we use vodka, because it is cheap and has no flavor.

vodka doesnt taste at all try it !

I'll agree as well. There is not taste when I use vodka.

If you can get Everclear, use that--don't drink it, smell it, or light a match near it, but I have used it extensively at this point and never get any taste from it.

I use vodka too with no problem, and it dries fast.

I can get the equivalent of Everclear, but when I run out of it, I've been known to use vodka or tequila (and neither leave any aftertaste).