shooting cleaning pellets ?

On my 22 caliber i use a length of parachute cord. Cut at an angle on one end and super glued for stiffness. Feed it down muzzle end then fold it and start angle cut part back into barrel making a small loop . As you push the angle cut back into breach end of barrel pull on para cord. This works for me and will usually get the barrel squeky clean. Also reusable and cheap. Sorry I dont know exact diameter of cord i use as there are different diameters but cord should fit easily into barrel