"I agree on that. But Mythbusters is an entry level program. It never really explains the theory."
This is what the value of such TV shows is ( hang on , you don't have a TV ? 
)
All the theory any kid could want, can be Googled.
What is the attraction of that, over say them playing with Facebook or BBM ?
All new ideas ( even if they turn out to be old hat ) need to be experimented with - which to me is the best part.
Shows like Mythbusters show how to set up an experiment, they don't go into elaborate detail, ( they have to entertain too ) but show for example how you need a control sample, and how to monitor external influences.
If they can get the kids to think and experiment, thats wonderful !