Grit guard

A grit guard is a rigid plastic insert, usually a grid or radial pattern of raised ridges, that fits into the bottom of a standard wash bucket. When you swirl a dirty mitt against it before reloading with soap, heavier grit and sand fall through the openings and settle underneath the guard, out of reach of the mitt on the next dip.

It matters most in the two-bucket method, where the whole point of the rinse bucket is to remove contamination from the mitt. Without a guard, grit just sits suspended or resettles on the surface where the mitt can pick it straight back up, which quietly undermines the safety of an otherwise careful wash routine. It is a small, inexpensive part that has an outsized effect on preventing swirl marks.

Most grit guards are sold to fit standard five gallon buckets, so check the diameter before buying if your buckets are a different size or shape. Look for a stiff guard that will not flex or pop out when you scrape a mitt against it. A common mistake is buying a bucket and guard as separate, mismatched items and finding gaps around the edge where grit can climb back up and bypass the guard entirely.