Because they rest against your sweaty skin throughout games and practices, shin guards need to be washed regularly. The fastest and easiest option is to hand wash your shin guards with soap and water. You can also wash shin guards in a washing machine. Place them in a washable mesh bag, which prevents any Velcro straps from sticking to or wrapping around other fabrics in the wash. Use a cold cycle, then lay the shin guards out to dry to prevent shrinking rather than placing them in the dryer.
To Tackle Smells
If your shin guards have gotten particularly smelly, a hand or machine wash may not be enough. While you may be tempted to spray the shin guards with deodorizer or disinfectant, the chemicals can potentially irritate your skin. To help alleviate any smells, use a wet sponge and scrub them down with baking soda. Kill the bacteria that can grow on the skin-side of the guards due to sweating -- and that leads to unwanted smells -- by laying them out in the sun with the skin-side facing upward after each wash.