Long story short, is it worth shielding your cavity? Been considering doing it to my RG, I play with high gain and was thinking maybe it will help get rid of a little of the hiss associated.
I was also considering this, a Decimator then?What Rob said. Your RG is probably already shielded with graphite paint in the cavity. Unless you're having issues with 60-cycle hum, more shielding probably won't reduce noise in your signal chain. Try turning down your gain and using a noise gate.
Close, but, no. You need copper foil tape with conductive adhesive. I use this. Of course, you could always solder the non-conductive tape together if that's all you have available.