Bleaching help

[kidgloves]

Hi, last Summer we laid down a bed of white stone chippings to replace grass.
Our cat used to 'do her business' on the grass (don't ask) and we hoped that the chippings would make her find somehere else.
Sadly this has not been the case, so now we have off colour patches where the cat has 'been'.
Can anybody recommend a good way of restoring the colour of our white chippings ?

[marvinparvin]

Get rid of the cat - this will probably please your neighbours too.