I used to use a product called Danzac for coating bullets.
My findings were that is was accuracy neutral, no better or worse than naked bullets.
For cleaning it did reduce the copper build up in the barrel, but did nothing to reduce the carbon fouling.
I seemed to aid in ironing the carbon into the bore, making it more labour intense to remove it.
I did clean as often as I would with naked bullets, to stay a head of what I felt was building up in the bore.
JB's was a necessary part of cleaning.
Copper is easier to clean out in my opinion, so no more coated bullets for me.
Like so many of our decisions, this is based on two barrels in two different calibers, which is a small sample
for making any truly meaningful judgement.
The recommendations of the day were to use JB's to scrub it out and Kroil to aid in getting underneath it
to lift it from the steel.
Nothing here that you have not already tried, there are a lot more solvents out there today, so maybe one of them will work better.
DanO