MoNoFletch
I use Windex between shots and after. I hit the barrell with Break Free Barrell Blaster (Citrus)...Then Bore Butter to finish.
Basically I do the same thing, only I use Zep Citrus - Cleaner/Degreaser - and instead of BB - I use the new TC T-17 patches on a hot/warm DRY barrel... They do not apply the lube much more evenly that tryingto get BB in the barrel evenly.
Couple things I would also suggest.... after your application of BB then go back in with a dry swab, a couple of them infact and remove all the excess you can. Let the barrel sit until it is completely cool (room temp) then dry patch again and for the final step use a quality bore oil in the bore. If you plan on shooting again in a short period of time just use a very light coat of oil... if you plan to store the gun for an extended time br a little more liberal with the oil in the bore.
A lot of people do not like the use of BB or any natural lube and will tell it is worthless. I do not use it for rust prevention, but I do use it for reduction of fowling and I believe it and the use of a synthetic gun oilmight be one of the reasons that I do not fight the T7 'crud ring' or terrible fouling. I have even begain using the T17 patches in my Trap shotguns - makes a ton of difference in the chokes and how much plastic they capture...
I can not come up with a good explanation of the 'white stuff'
underclocked's 'crud ring' is a baked on ring around the bore just above the breech....
Just thought of something, I assumed you were using T7 because you mentioned 'crud ring' - what powder are you shooting? The reason I ask is the old APP and it's look alike powders did/do leave a white ash type residue...