Well, lemme explain in a quick post.
People from Facepunch play this, and they liked to forget off a lot as Chemists.
After doing tons of mixing and research with newer and newer updates, they found out a combination of stuff and stuff that made a grenade and foam explode constantly, allowing other things to explode.
Also known as they made infinite foam, along with an explosive mixed in.
This could cause the server to lag for like 10 minutes straight, so they removed it and probably banned anyone who used it.