2 cleaners for you wabi. Otis 012 CU and Otis 012 PL. The CU is for copper fouling and the other is designed to remove plastic fouling. For years and years I have cleaned my MLers with hot soap and water and it did the job reasonably well. Decided to give that PL a swing since I use that on my shotguns. That stuff pulled a ton of plastic fouling out of my lands and groves. Hit it with the CU and 4 patches later the blue was FINALLY dissipating. I shoot a ton more than you since I'm always testing this or that out so I foul my barrels up pretty well. Try using that stuff on your other MLers and you might see a difference in them as well.