I'll pay you if you test me and I fail, is the most juvenile challenge ever uttered. If you are natural, would you let a random someone "test" you? Of course not, suddenly there are all sorts of preconditions on how to go about it and nothing happens. I had an idea on a "reality TV" type of show, hopefully well finded, where a crew rolled up to anyone claiming natural and offered a comprehensive drug testing packagr by a third party, and where they would "win" a good amount of money if they passed. Not a single "natural" would take anybody up on a generous offer like that. Not one, ever. But it would be entertaining if some wealthy individual funded that, perhaps with hidden cameras, in fact most would probably admit they wouldn't pass, if they thought it really was "off the record."
"We" know it's all bullshit, but it would still be funny, all these guys squirming and pissing their pants.