Crackle Medium

Commador Q

i picked up a bottle of Vallejo crackle medium, but the directions are a bit ambigious.

i was ondering if anyone had tried it before and what tips they may have for getting the best results.
if this is what i think it is, it dries clear, so paint it over a colour, or paint the colour you want on the part, then mix a colour with the crackle medium and paint over it. Or just mix a colour into the medium and paint it over your basecoat for a certain effect. Just test it on paper.