I just use a little pressure nozzle (brass or plastic -- but I prefer the brass ones -- about 2 or 2 1/2 inches long, available wherever things like lawn sprinklers are sold) on the end of my garden hose. If your tiles are really
bad, from years of not being cleaned, you could rent a pressure washer. You don't need to use any kind of chemicals., even vinegar. Just plain water under pressure cleans off all moss very nicely.
"Isn't it enough to see that a garden is beautiful without having to believe that there are fairies at the bottom of it too?" - Douglas Adams