So I’ve followed everything from Cybs’ Hybrid salt tek and thus far everything’s worked great, im just trying to figure out what to do with the leftover materials left in the jar? Is it safe to set it somewhere with the lid on it for a couple days? Or would it be smarter to discard the rest?

Hey

If'you're confident that you extracted almost everything, you can discard that.
If you want to experiment a b it more, depending of your storage method, it can be safe to be stored few days.
I had a basic mix let for few month and got few mgs more, nothing transcedental but it can be something more ...