When you have dirt on your golf clubs, it can add weight to your club, it can mess with the aerodynamics of the club, and especially with irons or wedges, it can take spin off of the ball.
After every shot, it’s important to make cleaning your clubs part of your routine. Using a wet towel and a wire brush (if you have one) will ensure that you’ve cleaned out those grooves and the clubs can perform optimally. Similarly, if you’re hitting balls on the range, before you leave, be sure to clean your clubs again, whether it be with a towel and brush, or using a wash station if it’s available.
After a few rounds, you’ll want to thoroughly clean your clubs to make sure you’re getting the most out of your equipment. Using a bucket of warm water and soap, take a sponge and clean off your clubs. The grips need attention too. Proper cleaning with soap and water will remove dirt, sunscreen or sweat that tends to accumulate on the grips.