All you need to do is find a section of water and continously go into it. You'll see after a while that your shirt will get cleaner. It may still have a faded dirt mark in it. Unless you want to make it 100% spend a few mins diving into the water (tt took me around 10 mins to get my White dress shirt 100% clean!).
Also, you can go into edit skater and change a small thing like: add jewllery, change skateboard etc. Either way, your shirt will be clean!
Xbox360Cheats.com is an unofficial resource with Xbox 360 cheats provided by members of the public. We are usually unable to test submitted Xbox 360 cheats, so please use them at your own risk.