I find that once a bike is "truely" clean, then keeping on top of it is pretty easy.
I "stripped" my 748 down two years ago, see "9 1/2 weeks" on the old board.
After that, If the bike gets really ditched (it has happened) I use a mild degreaser such as Muc-Off or Dirt Attack and give everything a thorough soaking. I then use a garden sprayer to clean in all the nooks and crannys, then use soapy water and the garden sprayer again.
I find the garden sparayer better than a hose as the volume of water is less, but you can actually get quite good pressure out of it. Lots of water and Dukes doesn't usually mix too well, especially if you have an early Datatool
Every once in a while, I pull the body work off and clean the chassis that you don't usually see.
I've never really liked using strong degreasers on the bike because of washing the lubes and greases away. The gentler cleaners work fine.
For polishing, I use Color-Glo every now and again, and Plexus regularly.