All the above suggestions will work. Also, a white vinegar soak before scrubbing can be an alternative. My bravo 3 props were so frosted that I had to use fine grit wet and dry sandpaper. Start with 400 and progress up to as high as 2000. Keep the sandpaper and prop wet during this process. Then use a marine polish and finish with wax. It's a lot of work but your prop will shine. Note: this worked for my bravo 3 counter rotating prop set which was not supper shinny when new. If yours is one of those "mirror finish" props, maybe avoid the abrasives or start with the 2000 grit if all else fails.