Cheers Charlts. Hope you are well fella.
Yeah I was wanting something to keep things central. The plan is to go in at the breech end and not come out of the crown end.
The metal rod I have at the moment has a screw on soft brush that is tight to push in so I could use that. I wanted a handle with bearings really and then use about 3 felts on the end and put the compound on that.