FWIW, I have been using the Magic Eraser to clean my two cartridges for a while. While this works very well on my Ortofon OM-30, it is less effective on my Denon DL-160. I would guess that the smaller stylus profile (which is how you get more detail from your LPs) of the Denon doesn't catch as well on the Magic Eraser fabric. I have had a stubborn dust bunny on the Denon that the Magic Eraser and a dry stylus brush have been unable to dislodge.
I am ordering an Onzow - hat tip to chakster.