If the crown gets gunked up, I turn the Watch off and run it under some warm water for a few seconds then dry with a soft towel. Same with the rubber sport band. No cleaning solution needed.
"Washed" my SS for the first time this week, as the crown got sticky. Just followed apples instructions (warm water trickle from a tap) and its fine. My black sports band doesn't seem to need much of a clean tbh.
I just use a jewellery polishing cloth on the SBSS and it comes up brand new every day, almost a month old, not one scratch, its a beautiful watch! Glad I spent that bit extra! The coating has really held up fantastic for me!