What I found works well for doing washes on materials that have the possibility of becoming tacky is to clean the surface with soap and water, then spray the item with Duplicolor Automotive Clear which drys without tackiness on softer rubber materials. After the top coat drys you can thin down an enamel paint with thinner, and finally apply the wash. The enamel will dry completely without any tackiness. That is how I did the wash on my Movie Masters Joker.