I read through some of it, I understand the grounding but I do not understand what you are touching to drain it. Snip the red wire from the fly-back that goes into the top of the tube and then what touch your screwdriver to the snipped wire coming out of the fly-back??
I use a "jumper wire" with small alligator clips on each end, one end on part of the metal chassis or any metal that will act as a ground.
The other end I clip to the screwdriver and use that to "brush" across the connections of the can caps. on the bottom. Usually if the TV has not been plugged in awhile the "bleed-off resistors" will take care of the stray voltages.