I shoot 45s and 9mm. The 45s are FMJ. The 9mm are plated -copper. I bought my first borescope. The groves in 45 barrels are coated with brass - no surprise. The 9mm barrels are coated with copper, again no surprise. I have read [here] that copper needs to be cleaned out. No findings for brass. I use Hopes cleaners. I also use brass brushes. How clean is clean for these deposits in the barrels? The deposits in the groves are quite distinctive. Thanks for your input