Well apparently it's performance ENHANCING so looks like we were all wrong haha
Even weed can be performance enhancing if you're someone with high anxiety. But it always struck me as highly suspicious that WC had the league's hardest runner and he just happened to have issues with a drug that clears your system too quickly to test for it.
He also shaved his head regularly during the latter part of his career.
Think it's been a part of footy for a long time at a guess.