Do you have bars with a scratched finish? Why? What type of brush are you using? Are you even using a brush?
Do yourself a favor and ask yourself these questions. You don't want to end up with a barbell stripped of its finish. This will speed up the oxidation, aka rust, process and leave you with an orange bar quick.
Below is a prime example of the consequences of a stainless steel or wire brush. This knurling on this Texas Deadlift bar does not go out all the way to the sleeves, so it is imperative that you are careful when scrubbing the barbell. If not, you can see that the finish comes right off.
Here at Bar Shield, we recommend to always start with a stiff nylon bristled brush, and only work to a brass or stainless steel IF NEEDED. Through testing different barbell finishes, we have found that a stiff nylon is sufficient in the majority of cases. Even with bare steel bars!