All natural shows in the UK are drug tested.The NPA tests are carried out by UK Sports to IOC/WADA standards.The BNBF have pioneered the use of off season/out of competition testing.Sure,some people could try to beat the tests but is it worth it? Firstly you risk getting tested positive-having to pay for your drug test,get a lifetime ban and be branded a cheat by your peers.Secondly,if you did beat the test you would know yourself that you had cheated and get no pleasure from any victories.Thirdly,what do you win-a trophy and a few supplements.
I have competed lifetime natural with moderate success(won regional qualifiers and placed 5th at the national finals) and truly believe that 95% are clean.I'm not going to worry about what others may or may not be taking as I have enough to worry about trying to get those glutes and hams in 
If others want to cheat that's up to them,don't be put off competition because you think your competitors might not be natural just get in the shape of your life and be a real winner.
I just hope that you really aren't that dump? Everywhere where they have competitions between men about size, strength, speed etc. there is doping. No matter if there is tests or not. So simple. When there is even a tin medal to win, there is somebody trying to cheat it for himself and you can't prevent that with any way possible. You must have heard Olympics, summer or winter, no matter. There have always been tests for competitors, but from 100% who have used doping, only 0.01% get caught. How the hell that's happened? One of the biggest sport event in whole world, and by far most money involved, and they doesn't have proper tests? If you try to put that to proportion, what is the probability that you have foolproof test in some natural bodybuilding contest? None what so ever, so it is futile to talk about natural bodybuilders. There is no way to proof that somebody is natural, so why make the claim?
You pass the test today, but what you were using last year? Did you juiced up first five or ten years of your training, then stop and claim you are natural. Prove that isn't true, if you can. There is no way in hell to prove that, so there is many shades of truth on natural bodybuilding. One of the funniest definitions for natural was a guy who was juicing heavily past 15 years, stop for a year and TaDaa!!!: here you have a natural bodybuilder. What a fucking joke.
If Ronnie stops and doesn't use any gear for a year, he can go for natural contest ? Well why not, in that time he is natural, no way to deny that...
If you have to define natural bodybuilder, there is only one way to do that: bodybuilder who haven't use anything, no chemical help what so ever never in his life and who can prove that. Can you prove that you fit in that definition? Nope.
