Let the cage air out for about 24 hours before putting your snakes in if you use silicon. Silicon fumes can be toxic prior to drying and hardening. I was using some silicon sealant to redo some glass cages about a year ago and was sick for days because I wasn't in a ventilated enough area. Definitely not pleasant for me, and I would hate to think how a chondro would react.
But aside from that, it does work very well to hold perch holders in place. I haven't tried the epoxy, but I am thinking of giving it a try in place of silicon for my next couple of cages.