Yes—most microfiber cloths can be washed and reused. The main precautions are to avoid adding anything that can leave residue or particles behind.

Best practices from the community answers:

• Wash with liquid soap or liquid detergent rather than powder, since undissolved granules can get trapped in the cloth and act like grit.
• Do not use fabric softener.
• Hand-washing with a small amount of liquid soap is fine; machine washing can also work.
• Some users boil the cloth briefly after washing to help restore the fibers.

If your concern is trapped grit: washing should remove normal dirt, but if the cloth was heavily contaminated or you can’t be confident it’s completely clean, it’s safest not to use it on expensive lens glass. A cautious approach is to retire questionable cloths to less critical jobs like cleaning screens or eyeglasses, and keep a fresh cloth for lenses.

So: washable, yes—but if you’re unsure whether all abrasive particles are gone, replace it for lens use.