I've received this Argyroderma crateriforme from ebay today. It looks like a really old one, with all those layers of dry old leaves. In my view it is just beautiful. :)
It has arrived bare root but just unpotted not cleaned. And it is pretty understandable because the roots and the substrate have merged into a solid mass. Maybe I made a mistake and I should have just left it like it is but I wanted to free the roots and let them breathe. Of course to do so I had to brutally wash it, while pulling out imbedded stones and soil and tear out roots themselves (at least they were dry and inactive which should have reduced the harm). At the end I could bare the roots but felt really bad I had to disturb the plant like this. Acclimation is hard even without such drastic procedures.
Well, after all the washing I first let the plant dry - and it took a while because of all those layers of dry leaves. Then I was thinking of putting it in dry pumice and just hope for the best but I felt so uncomfortable doing that that I decided to construct a paper towel skirt instead. I thought this way I can stimulate and reactivate the roots in a controlled environment (it worked before) and make the towel/root wet without letting the moisture touch the countless layers of dry leaves that could start rotting very quickly and easily. The plan is to wait until new tiny white roots appear and then pot it into pumice substrate. At the moment I'm still afraid I made a big mistake but we'll see how it goes...