You might laugh but :
Ages ago a friend of mine who owns several bikes swore by ;;;;;; yes - cheap bubble bath.
So I bought some cheap bubble bath and since then have used it for my wife's HD and my RT and now my 1200GS also. It works fine for me with a bucket and sponge and hose.
Also rather than always using wax polish on paintwork, I use household beeswax spray polish (the cheap stuff) good for the car and bike (brings it up a treat and any chrome on the HD or my black plastic panniers on my RT) and just occasionally give it a wax polish. (this tip came via a car dealer and when in the HD dealer recently I noticed they were using some expensive spray to polish the showroom bikes, I asked what it was and it was basically the same but under another name).