I have heard that 209 primer residue slowly builds up in the flash hole with a fouling that doesn't rinse out with water, you got to use a drill bit or something similar.
Naturally, that's not a problem with shotgun shells.
I only got two inlines, one is a target pistol and the other is a target rifle with a slow twist patched roundball barrel, neither are hunting guns, no provision for a field ramrod. They both use #11 caps.
I only shoot them in matches and dread cleaning them afterwards.