Consumer Reports recommends the Toro Recycler 20333 because of its very good ratings in ease of use handling side discharging and bagging and excellent mulching. The reviewer specifically liked the washout port for cleaning buildup under the sizable deck. The Wirecutter used to list the 20333 as the runner-up pick but supplanted it with the 20340 because of the newer models upright storage. However the reviewer still recommends the 20333 if the blade brake clutch is more important to you than compact storage.
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.
With the mower still on its side grab your socket wrench and wood block. Place the block inside the blade well. This is to prevent the blades from turning while you loosen their bolts. Remove the blade mounting bolt/bolts. A typical mower will have one blade like the Craftsman 37700 I serviced for this guide (one mounting bolt). Some like my Honda HRR216VKA have two blades an upper and a lower (two mounting bolts). Each blade should have at least two cutting edges.