The Best Homemade Shower and Tub Cleaner Double or Triple this recipe for a larger tub or shower! Ingredients 1/2 cup vinegar 1/2 cup Dawn detergent - blue bottle spray bottle Instructions Warm vinegar in microwave for 90 seconds. Combine vinegar and Dawn in spray bottle. Spray on your shower or tub. Let sit for 1-2 hours. Wipe clean.