The soap spray in the recharging kits works great, but often I have run out and had to use liquid dish-washing soap in hot water in the kitchen sink. Soap em up real good and let them soak for a while then rinse real good, let dry, re-oil and re-install. I have K&Ns on all my vehicles and do the same for all.

that spray from the recharge kit worked amazing. it washed out a lot of brown water and dirt and junk that didn't come out after i just washed with the hose. i was really impressed.

Another thing I do is, after the spray soap has loosened the dirt up I use the water hose or faucet to rinse from the inside-out of the filter. Hoping it pushes the dirt out the way it came, instead of from the outside pushing the dirt deeper into the filter media. Then lastly, wash the outside. Should be good as new.