I use a new cart & atty every day or two. When Sunday comes, pull the stuffing out of the used carts, rinse them out real good, wash the plastic tips and soak the attys in hot water for an hour or so. Rinse everything out real good, blow out the attys and set everything on a paper towel to dry. Later on, re-stuff the carts and I'm ready for another week. I rotate between 6 attys, have only had one die in 6 months. I never use anything to clean them other than HOT HOT HOT water, blow them out, let em dry, prime with a couple drops on the coil & good to go.