After ascertaining that my Anschutz 17HMR barrel was beyond help. I received a demo from an Anschutz tech on cleaning a barrel.
We then did the 1960s Weatherby 22-250
He initialy stated for periodic cleaning, the use of "Medallion" (can't find it anywhere) or KG12 on a brush for the 1st 6" for 30 strokes then 10 strokes for the remaining length.
Once this was done he pulled a pull through from crown to chamber and put 3 .22 (1 & 1/8)patches in the loop, coated with 303 and proceeded to pull it through, with a frighteningly huge effort. This was followed by alternate dry/wet patches. After about 20 repetitions the dry and wet patches were clean. Looking through the bore scope, the barrel was like a mirror. Unfortnately it was pitted as hell 1" up the barrel, but it has probably shot 10,000 rounds in it's life.
We then left some wipeout foam in for 24hrs and it was not tinged blue at all.

He seemed to think the most overlooked practice is the use of a water based cleaner being used on either a patch or a bore snake to neutralise the corrosive residue in the barrel, and this should be done very soon after finishing shooting.

Corrosive salts can't be "neutralized." They have to be removed. Water or water-based solutions are the best for that.