Do you guys have any tips on how to remove surface rust inside the lettering on a barrel? I cleaned the barrel after shooting but apparently I missed the grooves of the manufacturer name and model. I tried to use some more cleaner on the lettering but its still there. I thought about some sort of pick or toothbrush to get in there and clean but I didn't want to scratch up the lettering too much. Should I use the bore cleaner on the outside of the barrel to clean up this rust or some other solvent?