I think John Denner still has the funnels for $20.00 plus shipping. I just use the hot water tap or the water from the water heater and consider it the monthly flush of the tank...As Buffdog says, the heat dries the barrel and then a good cleaning with Hoppes AND then again a week later if you are using corrosive. Also, don't forget the breech face, mag, gas tube and flash hider if so equipped. Corrosive ammo residue will eat the snot out of anything..I've seen mags darned near eaten apart on the front lip.