Anybody tried this ?

https://www.hollandguns.com/m7...er-remover-8-oz.html

I used some several years ago that a friend gave. It will clean the barrel right down to bare metal.
I thought it worked to good, I like to have some fouling in my barrel. It did clean all the copper out which was what I was after.
I have used shooters choice and kroil mix for many years. it did not work as well as the witch's brew.
I use shooters choice and MC7 one application takes out all the copper. Then I finish with Cleansoil I shoot moly in some of my rifles, and it did not touch the moly in the groves where the witches brew did after several episodes of brushing.

I have two bottles of it. It works well.
On a related note, I have also used Remington 40X cleaner, JB's Bore Cleaning compound and Iosso paste. All are abrasives and will clean the dark carbon and copper out of your barrel.

There is a youtube video (Believe the target) with Erik Cortina interviewing Frank Green of Bartlein barrels. Frank says he has seen and a pic appears in the video of a rifle barrel scratched by using abrasives and a bronze brush together.

I've used abrasives with a bronze brush and haven't seen any damage based on my borescope but I can't measure groove depth or width by using my borescope.

So, just to be on the safe side, I am now using abrasives only when there is a decent carbon buildup. I also only use a jag and tight fitting patch with abrasives on it to remove the stubborn carbon. It seems to work okay. I use wipeout/patchout to remove copper and gilding metal. I still start with a bronze brush with regular solvent on it to break up the loose stuff in the barrel, then patch it out. I'm now leary of using a bronze brush with Witches Brew or any other abrasive cleaner.

After about 15 years of shooting centre fire, I realised that copper and carbon get deposited in layers after each shooting session of say 10 to 30 rounds. I clean after anything up to 100 rounds in my hunting rifles.

In the last 15 years my regime is to use Carburettor cleaner for the carbon and Wipeout with Accelerator for the copper. Note that the carburettor cleaner will eat up any plastic coating of the cleaning rod. Just use a stainless-steel rod and careful to not touch the stock.

I find that big bore rounds foul a lot more (416, 470 etc) and require several applications even after just 20 rounds.