the cleaner is equal parts water, alcohol, and window cleaner/ windex make sure the window cleaner has no ammonia. after painting wipe out your paint cup best as you can, then add a bit of cleaner and hold you r finger over the spray nozzle and shoot the gun, it will bubble back through the paint cup and clean it then dump that refill and spray it through till clean. it may take a few times but only uses an oz or so.