The CURED  acrylic clear coat acts as a barrier when using enamel thinner and can be safely used to clean up the panel liner. Lacquer thinner will definitely lift and strip the finish.

A great product to consider is Flory Washes. They are clay/water based and are easily cleaned up with a water dampened paper towel.

As to your question, clean up once dry, usually a few minutes. This makes for easier clean up.