When your bowling ball rolls down the lane, it collects oils used to give the lane its slippery feel. Without proper cleaning, the oils penetrate your ball, taking with it any dirt or debris it picked up along the way. The result is a ball that doesn't perform as well as it used to. Simply wiping your ball down with a microfiber towel after every shot goes a long way toward keeping it clean. After every dozen games, you'll want to do a more thorough cleaning to remove oils that have penetrated below the surface.
Do It Yourself
While taking your ball to the pro shop is the ideal way to not only clean it, but have nicks and pits removed, you can also choose to clean your ball at home. One method is to purchase bowling ball cleaner, spray it onto the ball and wipe away the oils with a microfiber towel, using a circular motion. You can also use rubbing alcohol to loosen oil and dirt deposits. Don't soak your ball in alcohol, as it will remove the paint. Finally, you can soak your ball in a pail of very warm water for up to 20 minutes. The warmth causes the pores to open and the oils to float to the top of the water. Make sure to tape over the finger holes with waterproof tape, or your ball could be damaged by moisture getting inside.