The Hoses Come Out
By the end of La Tomatina, everyone is completely covered in tomato. They bring out hoses to help clean people off, but it's not enough, so you have to fight to get the attention of the guys with the hose so they spray you. If you don't get clean enough here, you still have a chance with some of the locals as you make your way through Buñol town, and if that doesn't work, I've heard there's a river close by you can bathe in.