Drink plenty of fluids before the session. Learn to sweat profusely. Carry a small towel inside your keikogi.
Sweat. Then step back, produce your towel, and mop your brow, neck, forearms, nose, chin, brow again, and anything you can get away with.
Although you can't steal much time with a single application, if you develop this technique properly it can become an unquestioned, possibly completely overlooked, habit which cumulatively results in hours of time wasting.
Often you have to work hard to sweat.
