Starsan is expensive! I use a clean dish cloth and a little PBW. I dont scrub my bucket to hard to avoid making little scratches that bacteria could find and call home. Before I use it again another cleaning and Starsan right before the Wert goes in.
Star san is not expensive, filling a spray bottle cost you pennies and if you have soft water or use destilled or RO water that thing can last long. I think if a buy a gallon of it I wouldn´t need to buy more for the next 20 years.