No, its not similar to silicon sealant, its far superior for this application.
Its an anaerobic (active without oxygen) sealant that is rated at 1050kpa (around 150psi) and hardens fairly nicely, especially over a bit of time. Ive not had a leak yet - teflon (PTFE) tape isnt reliable in my experience, hence the change to the loctite product.
Id imagine if you're silly enough to twist your tubing to get it off, it might leak after that - but it would take a fair amount of pressure to destroy the joint.
PTFE tape is pretty damn average, I dont trust it personally after a few slow leaks like you're speaking of.
Heres a link to the product in question -
http://www.loctite.com.co/english/products/567.htm
Be warned, its not particularly cheap (but id imagine your electronic circuit wouldnt be either...)