Okay...
the reason still shoot, card , and turkey gun aficionados recommend the solvent is to get the plastic-powder and any other fowling out of the bore
When we were kids we remember the swimming pools with slides on them , in order to slide down it , it had to get wet - or you would hook up on the fiberglass clear coat , and get a hell of a burn on your ---- That was a exaggerated example to point out the importance of surface and friction -- the same kind of mentality ( but a dry one ) is towards the steel or chrome bore of your shotgun , the fowling , oil , plastic will somehow do something to some peoples wads ,and affect the patterns as it whips out of there at 1,200 fps -- I can only lend you my limited experience in that when I clean the bore out with a solvent - wipe it down DRY inside the bore - no oil my guns will shoot tighter -
At still shoots and card shoots , there is all kinds of concoctions and methods people use to clean out the bores in the lineup from what people say
good luck --Shannon