I used TC Bore Butter, TC Gorilla Grease, and TC bore cleaner for years to good effect and without any problems before I found out how terrible it was. I even used TC Bore Butter as an exterior protectant. My rifle got rained on and was left sitting after firing for more than a day on many occassions without any rust.

I've also used Frog Lube and have a good supply of Frog Lube that's still good that I bought back in the mid 2000s when it was all the rage for ARs. Despite the bashing Frog Lube got, it actually worked very well in ARs. I've used it on black powder guns as a bore treatment and general protectant and never had a problem with it, either. I actually think Frog Lube missed its calling when it didn't market their produicts to the BP community. It makes a great patch lube, cleans BP fouling very eall, and is a very good anti-rust protectant.

[Linked Image from i.imgur.com]
https://vcdl.org/