Formula No. 65 & Polish Cloth. Keep your guitar looking good as new, with Dunlop's Formula No. 65 & Polish Cloth Combo. The Formula No. 65 & Polish Cloth Combo is the perfect kit for fighting off grime and maintaining the luster of your guitar's finish. At Sweetwater, we love Dunlop's famous Formula No. 65 cleaner and polish because it adds shine to any guitar, without leaving behind nasty residue. Along with a 4 oz. bottle of Formula No. 65, the Formula No. 65 & Polish Cloth Combo includes a 100% cotton, chemical-free cleaning and polishing cloth - an excellent value on everything you need to keep your guitar looking its best.