I wipe mine down with a damp cloth. I also detail the finish with Car Guys Hybrid Wax. I clean the chain and cassette every few weeks with a degreasing agent like Simple Green and a chain cleaning device and brushes. I’ve never hosed my ebikes down.
Yeah, mostly a damp rag, for greasy bits, a mild degreaser on a rag, then on the bike, maybe followed with a water dampened rag to rinse a bit. I don't even hose down my motorcycles. I clean them the same way, with the exception of the wheels. They get mild soap and water and carefully rinsed with the hose. Less is more sometimes.
Spray with high suds soapy water from a spray bottle. Rinse with low pressure water from a $12 garden sprayer used only for water. Often it is easiest outside to move the tilt of the handlebar up as to not damage important bits and to flip the bike to work suds and water through the chain.
Seriously, soap and water works best as long as it is very low pressure. I had been using some shampoo in the soapy spray but now I stick to Dawn Professional 1-00 because of its high suds. This stuff is highly concentrated so cut it back 1-15 with water. Rinse. Then you can lube the chain with MucOff drylube. I always remove the battery before washing. Be gentile.