Metal rubbing marks in the neck of glass carboy

[Imbrue]

Used a carboy brush to clean some stubborn spots in my glass carboy, after rinsing I noticed that there are markings in the neck and I can see on the brush handle where it appears some metal has rubbed off on the glass. I tried soaking in oxiclean and scrubbing with a rough pad for cleaning dishes and had no luck. Has anyone had this issue and got rid of it? It doesn't seem like it would hurt anything, but I'm new and worried, haha. I did some searching and I can only find old posts that don't give much info on the subject. This makes me want to avoid use the brush in the future.

Edit* If I do use it again, I will put something over the handle. (Heat shrink tubing, thin hose split on one side, etc...)

 

[flars]

Try a paste of Barkeepers Friend. I had just noticed marks on one of my carboys. The marks weren't scratches though, just some color from my brass jet cleaner.
I use a drilled bung in the carboy mouth to protect the glass. Cut the side of the bung at a sharp angled to slip over the metal of the brush. It is like a bore protector when cleaning a rifle barrel from the muzzle.

 

[Imbrue]

I'll give that a shot. I'm hoping they aren't scratches, it's the first time I've used the brush and it looks like smudge marks around the inside of the neck. I may try a large eraser (new of course) and see if it rubs off with that. If it doesn't come off, I don't think it's in a place that it will hurt anything with proper sanitation.