I do not wash my bike often, but when I do I use Dr. Bronner’s Sal Suds:
Unlike Dr. Bronner’s more well-known pure Castile liquid soaps, Sal Suds is a concentrated all-purpose cleaner. According to the instructions you can use it on just about anything without fear of damage. Depending upon your cleaning task you can mix in more or less Sal Suds.
When I clean my bike—which happens so infrequently that anyone I ride with refers to my bike as the “dirtwagon”—I mix a healthy squirt of Sal Suds into a wash bucket and fill the rest with water from the hose bib. A few minutes with a soft bristle scrub brush and some low pressure water spray is all that is needed to get my bike into near new condition. Okay, as news as something can look after thousands of miles.
When I rinse my bike and allow it to dry in the sun there is no greasy soap residue that you might get with something like an all-purpose wash for an automobile.
This stuff is great because I do not need to worry about the impact that the cleaner will have on my landscaping when it inevitably gets washed off the sidewalk or driveway.
About the only downside I have discovered is that my disc brakes howl like a monkey on meth the first ride after a wash. Seriously, it is like I put polyurethane brake pads on my bike. For those of us who came of age on bikes in the 1990s, never forget Winwood Poly Brakes.
Note: I buy this stuff with my own money and get no compensation from Dr. Bronner’s. This is not some influencer pimping a product for money.