If it was water or water based cleaner it's no problem,and been going on for well,since Washingtons troops got their rifles dirty.
Our own Military has soap and water on the approved list of alternate cleaning agents for the M-16A2,though it is NOT the preferred method.
In addition there is no end to the number of water based cleaners commonly sold and used by Military,L.E.,and civillians.
MPro-7,MC-25,and many others are waterbased.
Water is the primary content in a Ultrasonic tank.
Just gotta make sure the rinse water is as hot as a guy can stand it,and make sure all the water is either evaporated or blown out when done followed by a good coating of lube/preservative.
With all that dust and sand combined with the dry climate in Israel,I can see them using a water/detergent bath or sonic tank as routine before drill turn in.Otherwise the troopies would be forever with the toothbrush and never make it back home from drill!
Keep safe!
S-28