My experiences with roach barriers:
* Vasiline: Works, but gets messy with higher temperatures.
Roaches don't like to walk over.
* Silicone: I have the feeling that it's more 'sticky' and works better. It also keeps its consistency with higher temperatures.
Roaches don't like to walk over.
* Teflon grease: No experience with...
* Fluon paint (teflon /PTFE suspension): This is a milky like water based fluid with teflon particles. I use it diluted and paint it on the top of enclosures. It works very well, but after a while it get's a kind if dirty and effectivity decreases. So I need to repaint it every few weeks (just put it on a cotton and swap it over).
Roaches cannot walk over as they cannot get a grip on the surface. But small nymphs of good climbers tend to be able to cross it if it get's older. Larger roaches have a very hard time.
And yes, I have applied silicone and teflon paint many times with the roaches inside the enclosure. It's only hard if you have daring escape artists.