If you let it set up, you will find it very hard to remove. You can try soaking the metal parts of the airbrush briefly in a weak ammonia solution. I say briefly because if the airbrush has brass parts the ammonia will react with and weaken them. This may not be critical for airbrushes in the way it is for ammunition cases, since the pressure is so much less, but why damage an expensive and delicate tool if you can avoid it? Window cleaners with ammonia may help here, since they generally contain detergent and alcohol. As I understand the chemistry, the floor finish is an acrylic polymer whose molecular bonds are degraded by the ammonia, alcohol, etc. Acetone or nail polish remover might also work, but plastic and rubber might need to be protected.-