I've been reading the Onzo Zerodust leave a residue and over time it will ruin your stylus. I'm hoping it's not true, so just in case I purchased the Mofi LP#9 Stylus Cleaner. Comes with liquid and a small brush.
Humminguru S-DUO
I'm as nervous as the next person about water or any other fluid getting inside a cartridge. But with great care only the stylus and the tip of the cantilever get wet with this device. Here is a nearly new Cadenza Bronze (6 hours play so far) that has been brushed with a carbon fibre stylus brush:
and here it is after 20 seconds in the S-DUO:
And I was even wondering if the device did anything! Looks like it does.