The link I posted says they're pretty much harmless.
They feed on mold.
Washing everything seems like enough.
I wouldn't worry much, myself.
They may have come in on something else and set up house or the humidity spiked for some reason.
I've had a rip of a time with the heat/humidity wave we just had.
Ran a fan 24/7 just to get humidity in the enclosures under control.
Putting paper towels in seems to have helped 'soak it up' somewhat.
I bought aspen shaving at petco and got a bunch of red spider mites everywhere.
Threw out the shavings, cleaned the mouse tank and now they're gone.
They didn't bother the snakes but they tormented the mice something awful.