I used to have all sorts of hassels with cleaning barrels, and tried various types of solvents like Hoppes, Butches, Tetra, Short Scrub, and Sweets and others I cant remember.
Tried different types of brushes nylon or brass or stainless or none at all.
Tried different time frames as well, some 10-15 minutes, others half hour and others for a few hours. The only consistent result I got was the missus complaining why I didnt spend as much time with her as I did cleaning the Guns.
Hey some of you might already have a favourite cleaning system but mine helped me so I would like to share it with other shooters. It was also a bit cheaper in the long run.
I use 2 long plastic solvet droppers to suck up and put the different cleaning products in the barrel, it gives me a more efficient, precise and cleaner delivery method.
I use a kitchen timer to let me know when the Seweets has been in the barrel for the recommended time.
I also use my finger over the muzzle end of the barrel to contain the cleaning products and help create a vacuum to disperse and agitate the cleaning products through the barrel. You can vary the use of your finger to move the cleaning products through out the barrel. WATCH OUT FOR YOUR FINGER IF YOU RAM THE BRUSH DOWN THE BARREL TOO HARD IT WILL POKE YOUR FINGER.

STEP 1. Clean carbon and powder residue out with a nylon brush and Mineral Turps. Place Mneral Turps into the barrel from the chamber end of barrel using plastic dropper, hold your finger over the muzzle end of the barrel. Takes me about 3 goes to get it to be clean enough but not perfectly clean for the next step. After each time you do this clean out with a patch. Wipe Mineral Turps off rod and brush.

STEP 2. Use plastic solvent dropper to suck up Sweets 7.62 solvent and put Sweets into the barrel from the chamber end. Then get cleaning rod with nylon brush holding finger over muzzle end of barrel and scrub Sweets through out the barrel. I sometimes dont put my finger over the end of the barrel untill the brush is nearly at the breech end of the barrel, so that the Sweets has a chance to be pushed to the muzzle end of the barrel, once I do this I then use my finger keeping it over the muzzle end to help saturate the whole barrel, this helps to foam up the sweets and brush it in as well. Leave Sweets for the recommended time using the kitchen timer. After each time you do this clean out with a patch. Wipe Sweets off rod and brush.
It usually takes me about 3 to 4 sessions with the Sweets to get my barrel clean. Repeat STEP 1 once, to clean any residue of the Sweets from the breech, barrel and muzzle end of the barrel.

STEP 3. Using the eyelet attachment, put dry patches into the eyelet and wipe the inside of the breech, barrel and muzzle, including the outside of the muzzle to clear it of any excess solvents. I normally use my finger on the end of the eyelet with the patches wiping the very end of the Muzzle end of the barrel to remove any left over solvent.

STEP 4. Pass a clean tight patch through the barrel to ensure the barrel is free of any solvents or substances dislodged during the wiping out step 3. Finally check that the barrel is clear of any particles by looking down it, if none are found you are ready to fire your pride and joy.

NOTE Instead of using the plastic dropper you can use a plastic hypodermic syringe. Dont use the ones with the rubber piston they must be all plastic. I got mine from the local vet, they were used for giving cats a measured dose of antibiotic orally.