I clean with clean bore guides. I foul with fouled bore guides.
And no reason for expensive precision fitting per cal bore guides just for pre-fouling. So I use an auto parts store piece of fuel line.
Just keeping the tungsten out of the chamber/action.
They were a preferred load. Went out with them again later in the fall. At 200 yds. placed 5 rounds in a 1" hole. I keep these rounds for the cooler season and into the early winter for hunting.