Ostrich feather duster.
If a bass needs a good clean, like the last bass I bought, I use a flat sponge pad and water of about 65 degrees with some washing up liquid. Cut the strings off, squeeze the sponge pad out so it's barely damp, at that temp it's evaporating off as you are using it. Then lift the front end of the sponge as you move forward rolling it back to lift the stuff off. If there is any grit left on the bass, and you hit it with the usual polishing motion, it will leave a skating rink effect, which looks particularly bad on black painted basses.
Some bees wax polish for the fretboard (sprayed onto the rag), then micro-fibre cloth the whole bass over.
I've found that spraying stuff on a gloss finished bass, usually ends up collecting in the pickup routes or around the edges of the bridge plate and other fittings.
For hands that do dishes to be as soft as your bass, use Mild Green Fairy Liquid.