MK6+ RTV insulation

update 2
I tried again. When the first attempt failed, I peeled off all the RTV and it turned out I had put about 1/16 inch of insulation on it... I redid it, this time making sure I applied it thicker. I also did about 3 passes. I have much closer to a quarter inch of RTV on it, and its printing well. As I type this, I've been printing for 1 hour, 23 minutes without the shutoff kicking in, and the M3s through the acrylic are not too hot to touch. Neither is the RTV.

update
So far, so bad. It really didn't insulate enough. My ToM heated up and ran for a few minutes (maybe 10) before the safety shut-off cut out. Its weird because it seemed to me that the insulation itself wasn't too hot. To my finger, it was cooler than the extrusion tip. Looks like I need more, or a different silicone, assuming it can be done with silicone at all.
end update

I started building the new hot end, and decided I didn't like the insulation. its the least professional bit, imho. So I went looking for an alternative. This is my first try: RTV. Its good up to 370C and vulcanizes, as it sets, in 24 hours.

Ok, so it doesn't look any better, but its mine, ya know?