Remembering my organic chemistry labs we were taught to discern organic components using their smell (thanks Dr Wilson). To my nose, the alcohol component in Tamiya's thinner smelled remarkably similar to Expo Dry Erase board cleaner. I procured a pump bottle of the stuff from the office supply cabinet and tested my hypothesis. Worked like a champ. When your hobby shop is closed or too far a drive - check out the local Staples office supply store.
As always, test a new material/process before committing to your current masterpiece