It's my understanding that, in order to get the maximum benefit of using moly, both the bore & bullet need to be treated........so what Jim told you makes sense. But like you, I have a hard time just letting stuff stay in the barrel like that - I'd worry about copper & powder residue that might be trapped next to the metal under a layer of moly.

Now they do make a moly paste that you can run down your barrel before shooting the coated bullets - similar to "seasoning" a muzzleloader barrel. That seems to be the way to go.......coat a clean barrel and then shoot the coated bullets.

However, I would still clean and strip all the moly out once or twice a year to be on the safe side - better to put in a little extra cleaning time, than it is to find a problem a little too late!