shockwave settings

I use facebook and am unable to put messages in the gift requests so someone suggested emptying shockwave cache, Shockwave Flash Shockwave Flash 10.1 r102 is the add-on I have on Mozilla, but I can't find how to empty cache, I've tried downloading adobe flash player separately on computer but the only thing that I can get to come up on my desktop, is install_flash_player.exe, nothing else, any ideas how to clear cache for shockwave flash or completely install adobe fp so I can clear cache, thanks