Stylus cleaner

My best investment was in a 60x magnifier, got one for less than $10 on eBay and this lets me see the dirt on the stylus. With a quick dip in the Oznow after every session (or hour or so of play) and a go with the Audio Technica ultrasonic moistened by Last #4 stylus cleaner once every couple of months. Main thing is to be gentle and don't let the dirt build up

As many have noted the key to a good cleaning regime is actually not letting the stylus get dirty in the first place so

1. Clean LPs
2. Inspect and clean tip at least once each session (Oznow Zerodust or magic eraser)
3. Keep dust and dirt away from cantilever (i.e. keep the room clean)
4. Infrequently more thorough clean with brush/liquid or ultrasonic

As it's step #4 that is most likely to damage things it's the one to avoid as much as possible and if you are doing #1-3 regularly you should not need to go to step #4 very often at all

This one is widely available and works well. You will have to remove the clear plastic guard

Microscope