I have been training since I was 13 (20 years now). In that time I used gear on and off for 3 years. I have been clean for over 10 years now. Since then, I lost ALL the juice muscle I gained and then some.
That said, I say open this up to any Get Big memeber that has 500+ posts...clean or not. There is no real way to tell who is clean. I'll bet that a good chunck of the "naturals" are really closet juicers...
As for my chances, if we are talking 12 weeks from now, they are not so good, as I will be doing endurance training. I may be lean, but I will have little muscle. Either way, this would be fun...