How to get the dirt out of the rocks in rock landscaping ...
Then use a garden rake to jiggle the top layer of rock to break up the soil that embeds between the pebbles and bribe your spouse to blower the spot you are jiggling (oh you do have a dirty mind!). This will give you some satisfaction and would probably be "good enough" for an annual cleaning, but if you've been lax, you may want to get down a few more layers then a blower or power washer will ...