It can be done both ways, but doing it manually, not automatic is more efficient. To get all of them. But requires lots of time to get it done, in the other option, it can morely delete some files which isn't supposed to. It might detect some files here and there which it'll think it's a "Character File Detection" Which I'd not take risk to.
To be exact, it's being done manually. But I may have written something different in other posts, such as this: http://forum.pandawow.ru/showthread.php?t=174886&p=1068645&viewfull=1#post1068645 - Understandable, and sorry for that.
The main reason why it's being done, which I think is because the Database is too large. There's a limit. If it's maxed, more money need to pay to enlarge it. So instead of paying more money, we just delete inactive stuff. It doesn't affect any ingame MS, only if it gets too large and not dealt with. Just a brief description of it, so you know.
If this would be done right now, it would be a bad time. There's other things which is more important than the cleanup. If not, Juster/Zeox will notify us.
Anything else?