Before recycling I used to put the TV set on a tarp and let
my kids pitch rocks at it from a good distance.
Aquadag coating should be washed off as BJ says.
I remember being instructed in my military electronics training
that it was not good for you. I did a quick google but didn't find out why.
It's messy nonetheless. A friend of mine has been successful in leaving
on the electrical connection and creating a cool biface too.

Zuma