Not really a "gardening" topic per se but does anyone know a non-chemical, or at least an "earth-friendly chemical" method of cleaning moss from patio bricks. I'm pretty sure they are just ordinary house bricks used as a patio just laid down on sand. And I'm sure they are pretty old too - maybe the moss is holding them together - so whatever I use can't be too corrosive.

I use 1300 psi pressure washer to clean patio, driveway and outdoor furnitures. No chemicals, just water.