How to clean Karat 17D3 stylus?

Audioquest make or made a device that provides a tiny circular pad upon which you sit the stylus tip. Then you press a button and the pad vibrates at something like 400-500Hz, to loosen any particles that may be adherent. It's very effective, especially for dust balls that may work themselves up into the body of a cartridge. Over the decades, the device has been marketed under the "Signet" brand and lately under the "Audioquest" brand, and maybe some others. I have seen both brand names on different samples of the identical device. You can probably buy it from Music Direct or some such mail order company.

Have you examined the stylus and cantilever under a microscope?  That will tell you how dirty it is now.  Then you can have another look after whatever cleaning procedure you decide upon.  Yes, the cantilever is very short (17mm), but I am not aware that cleaning the stylus is especially fraught, compared to cleaning styli on longer cantilevers.  I'd use Stylast #4 followed by the Stylast stylus brush, carefully. ((I've got a 17D3 too, and for casual cleaning between sides I have used Magic Eraser.)