Hi J., I am sure that I have the answer for you, but it is a matter of exactly which product will work best. I would try Shaklee's Basic H2 in the degreaser ratio first. Basic H2 is used to clean windows & mirrors in one ratio (2 drops Basic H2 in 16 oz. of water in a spray bottle), general purpose cleaner for walls, woodwork, countertops including granite, appliances, etc. (1/4 teaspoon in 16 oz. of water in a spray bottle), and as a degreaser (1&1/2 teaspoons in 16 oz. of water in a spray bottle). This is an awesome product, and it is GREEN! It is non-toxic so is safe for you to use and safe for your family as it has no toxic chemicals to poison your family or our environment. Also, it is cheaper to use than whatever you currently use, as it is heavily concentrated -- that's why you use so little to mix with water. One bottle of Basic H2 will last the average household about 10 months anyway and will allow you to throw out your toxic cleaners such as: Comet, Windex, Fantastic, etc. Where do you live? I am in Georgetown. If you are nearby, I will be happy to give you a sample to try on your shower door. You will just spray it on and wipe it off with either Shaklee's microfiber cleaning cloth (which can be washed & dried at least 400 times before buying a new one) or a paper towel. If you are not near me to get a sample in person, I could mail you a sample if you wish. Please let me know if I can help you. You may read more about these excellent Shaklee non-toxic cleaning products at my website www.emilytaft.com - just put "cleaning products" or "Basic H2" in the search box. You can reach me at ____@____.com or ###-###-####, and I will be happy to chat with you. Hope this is helpful. E. Taft