There is another product known as "gnatrol" that I use in my greenhouse to keep fungus gnats away. It's basically a purer and cheaper form of the mosquito dunks. It's also fully soluble in water. I've used it on a few roaches species before and it doesn't seem to affect them but it does kill springtails and isopods so I'm sure if there's any leaves:wood in the enclosure that the roaches primarily consume it may cause some issues.
Sorry to resurrect this thread but hisser nymphs are serious escape artists and with most airtight containers of you allow the nymphs Togo without food long enough till they are skinny they can indeed squeeze their way under the foam seal. a product I'm currently testing that so far works waaaay better than Vaseline and is vastly cheaper than fluon is silicone "personal" lubricant applied very thinly using a cotton ball similiar to how ant keepers apply talcum powder as a barrier. So far it's stopped some of my fastest and best climbing ectobiids dead in their tracks without causing any harm to the tiniest of nymphs. While I still need to test on a species with even smaller nymphs as it does trap fungus gnats occasionally it seems to be working pretty fantastically and I'll never use Vaseline again(: