I love using my stainless steel fry pan. High heat is not recommended and may cause a mottled, rainbow-like "heat tint". This is natural to all stainless steel and is not harmful to foods cooked in the pan or to the pan's finish. Start with medium heat and reduce to a lower setting once the liquid is boiling or meats are seared. Also allow cookware and lids to cool before placing in water. This should help in not having to clean your pan with chemicals. The rhubarb sounds like a good idea to me. I will give it a try if needed!