What devices have you found useful when inspecting your stylii for cleanliness?

If your SQ is only CD-like, you have a way to go. Hi Rez streaming is a legit alternative to vinyl, but, IMO, high quality vinyl has it all over RBCD.

usb microscope.  connects to laptop.  can use it for vta adjustment too so that u get that perfect.  will change your life.  make sure you get a little stand too as the zoom u want is 140x and at that zoom you need something to help u make controlled movements with it.  

@rauliruegas  I pop the stylus into the Magic Eraser before every side. Been doing it for decades. Decca cartridges.

After each side, really? well you are anal about and that’s you but through many years looking/reading several web audio forums this is the first time that a gentleman likes to do that.

I use the magnifier on my iPhone, which zooms in more than I need, and a flashlight. I no longer use any cleaning fluid on my stylus. Years ago I had an expensive Grado Reference and my cleaning lady bent the cantilever. Grado agreed to straighten it (for free). I'm pretty sure Mr. Grado helped me. Anyway, when I talked to him over the phone about the stylus he said, "Quit using that gunk to clean your stylus. I had to clean it off. A diamond stylus is so hard that dust comes right off with a brush." Soi, I now use the Clearaudio stiff bristle brush to get off random dust particles as well as dust knots. I also use a soft bristle brush to clean off the bottom of the cartridge where dust sometimes collects. 

I use the onzow zero dust stylus cleaner.  Just lower the needle down a few times and voila - cleaned. Frequency depends on you.