I have two suggestions for you for future show subjects. The first has probably been mentioned to you before, but one of the dirtiest jobs I have ever seen is at an oil change and car maintenance shop. One of my best friends is an assistant manager at a shop like this in Hamilton, Alabama. I am constantly seeing him and his friends with oil all over them, and also having scrapes and bruises all over them from working in "the pit" underneath the cars that drive in. They often work with older cars that have many problems and odd features, so they are always having to crawl underneath things and work with very messy and oily vehicles.
The other suggestion that I have for you is as a Network Technician. This is a job that I had for a few years a while ago, and may sound like it's easy if you know what you are doing, but I assure you that it isn't. I spent many days in the muggy heat of Alabama when it is over 100 degrees in attics and crawlspaces running computer network cable for schools. Most of the time, the attics were downright filthy. I can recall once when we had to drill a hole in the wall at an older school to run some cable through it when a mountain of dead bugs came flowing out of the wall. It was sometimes very dangerous as well because we would often be working under something or above rooms where we weren't sure if it would support our weight or not.
If you would like any more information on these two jobs and where they are, you or someone at Discovery can contact me at danielhorton[at]gmail[dot]com. I'd be happy to tell you more about it and can get you in contact with the folks who work these jobs.
I think both of these would look good on TV, hope you guys will take them into consideration.
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