Parroting everyone else- warm water and dish soap- I find fairy liquid to work very well. After I soak it in fairy liquid and water I leave it in a separate cup of water to get any stray stuff off,then let it air dry. After cleaning it should be very grippy and rubbing it with your hands should make it squeak. I only clean buckings after a large amount of usage,About 30,000 rounds or more,keep in mind I use a bolt action rifle so with an AEG you can leave an even larger interval like 50,000. i always kill two birds with one stone by taking the opportunity to give the barrel a nice thorough clean and polish while the gun's gutted.