Redline S1 or Amsoil PI, both engineered to clean with PEA (polyether amine) and be an upper cylinder lube. Most other PEA cleaners have a fraction what these two have. Always check the msds, PEA % should be noted. Most other cleaners are solvent based not detergent like PEA. Explain how adding a solvent to a solvent will clean better? Sea Foam is great if used in crank case or vacuum straight into combustion chamber. Upper cylinder lubes are great, but you probably don't want to use them on their own long term, maybe run a little techron every couple months if you just use lucas.