LOL...
Crowler,
Yes, they will randomly select several competitors from each class and do a search of their belongings and/or even chemical analysis of a sample of their color.

J/K!
They won't necessarily know, but a trained eye can tell. DreamTan has a bit of a glitter to it, so much that it can even be used w/o oil (or Pam). It looks great on me, but not on other competitors. I think its b/c I have such silky smooth skin from my years of using Avon products... LOL
Supposedly, its tough to get out of fabrics, etc, so it screws up the upholstery (even worse than ProTan...). The promoter where I live bans it from all his shows.
I love the stuff. Goes on great, only 1 coat the night before with a good morning touch-up and you're ready to go. Comes off REALLY easily, compared to Pro-Tan (and Jan Tana). One shower and you can wear normal clothes. Its always washed out of my clothes w/o a problem. Great product. I now have about a half-dozen unused jars of it. Maybe I'll get a chance to use it at a National show someday...
-Randy