I know that many people prefer to hose their mowers down with a garden hose. I admit I have done it. Still doing that is risky. If water gets into the wiring air filter or engine you could really do some damage. Hand washing with damp rag is a drag but also your safest bet.
To clean it first start with a cool engine. If your mower has a fuel valve switch it off. If you can disconnect the spark plug too. Next use a leaf blower to blast away any old dirt and major debris. Now gently lay the mower on its side fuel cap facing up. Try to get rid of any junk on the mowers underside as well.
The reviewer at The Wirecutter said This Honda is in a class of its own. He was impressed with how the mower cut grass into smaller pieces with its double-blade design. And he found the Versamow system incredibly helpful. However the reviewer that it was tedious to adjust each wheel when he wanted to change the cutting height.