Originally Posted by PirateJim
A small brush with brass bristles will do a good job of getting ground in grunge out (NOT steel bristles!). Barkeeper's Friend is good but I wouldn't be concerned using Comet or whatever you may have under the sink, golf clubs are pretty tough by design.
I wouldn't use Comet, Ajax, or any other abrasive cleaner on chromed irons or highly polished finishes, unless you want the bright shiny finish to wind up as a satin finish. Also not good for painted surfaces. Bar Keepers Friend or Bon-Ami have a very low abrasive content so they should be ok.
I'd also stick with nylon bristles instead of brass, even for the hard gunk. Just let the head soak in warm water with dish soap (I use Dawn) for a longer period to loosen up the crud.
Ball marks on the top of woods (I know, none of us make these, but they might be on a club we bought second hand) can be buffed out with automotive polishing compound, a damp cloth, and a LIGHT touch. It also works well for polishing up a set of chromed irons.