Because Winn grips have absorbent properties, they may eventually soil from dirt and perspiration from your hands. This does not affect the performance of the grip.
To clean a Winn grip, apply a small amount of water or rubbing alcohol to a soft towel, and gently rub the grips. Do not saturate the towel. Never use a brush and soapy water to clean a Winn grip because it may damage the top surface and destroy the tackiness and slip-resistance of the grip.