Question about springtails and woodlice

[Pareeeee]

I've heard people talking about adding springtails, woodlice and earthworms to vivariums to help with soil culture etc.

Are they safe for crested geckos if they happen to catch and eat them? Do they really help in the vivarium, and where do you acquire them? Do you just capture them from the wild, quarantine for a while then add to the viv? How can you be sure you are not adding harmful parasites and/or bacteria to the viv? In other words, how do you "sterilize" the creatures?

I already know how to breed woodlice, I used to do it when i was a kid, lol, I liked bugs.

I've just overhauled Rodney's tank (see my other thread, same subforum) and wanted to do the best possible job with it.

Any and all advice appreciated. Thanks.