hmmmmmmm.....that's interesting. I own one rifle right now and it never shot very well, so I can't say I have much experience with whether or not it shot better when fouled vs. clean. The rifle shot so unpredictably, that it's now at the gunsmith being rebarrelled, trued etc....
I'll apologize now if I'm about to ask an elementary question, but.....
If you find that your gun shoots better when fouled, and you only clean it when you notice your groups starting to open up, why bother with 'breaking-in' a new barrel? I understand that process to be shoot once, and clean and repeat this process for ten rounds, then gradually shoot more rounds between cleanings. At what point is the barrel broken-in? and if a gun will shoot better fouled, why bother?
I'm not gonna shoot here. I'm gonna shoot waaaaaaaay over there!