My 14 year old cherry kitchen cabinets are looking a little dull. The lip of the raised panel is looking grey, rather than the rich cherry color. I don't need to do a major refinishing job and I don't want to damage the wood, but would like to know if I should use fine steel wool , fine sandpaper or something else on them before I urethane them. Also, what's the best product to use to clean the cabinets before starting this project?