[Retr0id]

I use isopropanol to clean mine, works great. I just use toilet paper for the cloth, but combined with the isopropanol you don't need to apply any pressure, so scratching doesn't seem to be an issue.

[chicob]

Isopropanol also evaporates quickly, so if there is any dirt left behind one can immediately see it.

It probably would be more than enough to clean the hair brushes, instead of the ultrasonic thing.