Well, I never "tried out" for anything. Along with a bunch of my friends, I was in the background of a few scenes of a crappy old Disney movie they filmed at our County Fair one year. (I was washing my cow, mostly out of focus, while Randy Quaid and Christopher Lloyd are having an argument - back when they were still young nobodies.)
I was in a bunch of "Discovery Channel" type of shows back in the 90's. Sometimes a producer would come visit and then decide not to use me. e.g. for Bill Nye's show. After doing a few of these, and watching similar shows, I gradually learned that if the producer thought that your work was visually boring, they would always interview you while driving your car or climbing around on rocks. Go watch... you'll see what I mean.
One of those took three days of filming for about ten minutes of air time. I took the camera crew for a field trip in the Grand Coulee. They seemed most excited when they found that my day pack, that I kept in the back of the 4-runner, was the same color as the car.
(Yes, so gay, but apparently telegenic.) Most of one day was spent just driving my car up a dirt road, while the camera and the director were perched on a cliff, with a walkie talkie, telling me what to do. They were trying to get the dust plume to catch the sun just right. At least their intern washed my car between takes. Then we climbed around on the rocks, while I hammered out some samples with a rock pick, for no particular reason. (The really interesting rocks were back in the caves, where there wasn't enough light.)
When they finally asked questions about my work, it was getting dark. They suckered a spotlight onto the windshield of the car. The director and the sound man in the back seat. Camera guy rode shotgun. Then had me drive down a cliff road with no guard rail, in the dark, while they asked questions. I couldn't see a damned thing with that spot in my face. I guess that terror came across as enthusiasm in the footage. (O god O god, we're all gonna die.)
After all that, they edited the interview to make it sound like I supported something that I totally disagreed with.
Another interesting show was a local Spanish TV news segment. I was all worried about my virtually incomprehensible Spanish skills. But... the news reporter was this long, tan, supermodel-looking chick who was wearing hot pants, string bikini top, and spike heels. And a hard hat. In an old mine.
Which was great, because it didn't matter a damned bit what I said or tried to say. "What? There was a dude in that shot?"