The bore mop is sort of falling out of favor these days.
When used to apply protective lube inside the bore, the mop gets dirty and you start carrying dirt and grit into the clean bore.
When used to apply bore solvent, the mop very quickly gets fouled with dirty lead and copper fouling that, again, you're running through the bore, re-fouling it.
These days, most people use clean patches for every pass down the bore whether with lube or solvent.
I suspect the sales of bore mops has fallen off greatly, especially in rifle and pistol calibers.