Eesh, that is nasty. I recently had an outbreak of these mites on my Ts (<edit> crickets!) including my 0.75" GBB sling. I wasn't able to find any way of removing them from such a tiny T. I changed the substrate and haven't fed it since, and will continue not feeding it until either the mites are gone or it starts to loose body mass. That's all I could think of.
Sorry I don't have any more advice. If it's any consolation I think the mites cause us way more stress than they cause our spiders! Good luck with it though.