Clay pots gradually whiten with age, showing evidence of minerals leaching from water through the years. Here's how to get that charming, weathered look without waiting.
Source: Martha Stewart Living, March 2002
Medium-grit sandpaper (about 150 grit)
Stir 1 cup of lime powder, a mineral available at garden centers, into 2 cups of water until it takes on a thick, gravy-like consistency. With a bristle brush, paint the solution onto pots, sparingly in some places and generously in others.
When the pot is completely coated and still wet, spray some spots with water from a spray bottle on the "stream" setting to let some of the lime solution run off.
Allow the pot to dry, then sand in a random pattern with medium-grit sandpaper (about 150 grit) until you are satisfied with the gently mottled surface.