How come no one ever thought to do this?
Bury the canister in 100 feet of solid concrete? Or place it onto a rocket and launch it into deep space? Or drop it into a nuclear reactor?
No, let's just keep the scary green liquid swirling in the creepy canister locked away in the even creepier basement of the really creepy church, surrounded by all of the creepy homeless/soulless people. That's a much better idea!