Nothing beats KORG's muslin swaddling cloths that they were handing out at Superbooth a few years ago, for cleaning those knobs and hard to get at clavier keyboards. It was such a great bit of Superbooth swag that I went down the rabbit hole on Japanese swaddling cloths, muslin, and the like[1], and am now a convert to the muslin clan. I don't use anything else for swims these days, its that great. The fact that I ca…
FYI -- swaddling is the practice of binding up an infant's legs and arms, and other appendages, so that they can't flail around, or swat at adoring shepherds, or fall out of a manger where you've laid him. The "swaddles" they're selling start at 115cm square. You probably do not need such a large cloth to swaddle your KORG keyboard.
They work so damn well that I've standardized on muslim swaddling cloths for many other things too - perfect for the beach, picnics, etc.
And no, one doesn't swaddle ones synths, but rather makes them sizzle instead...