I will say that I was quite impressed when CleanMyMac 3.app cleaned up a small problem that Onyx wouldn't and also Trashed some old files that provided some extra free space on my hard drive. Neither does the Application hold the user to ransom as some other cleanup programs have a nasty habit of doing. I don't know about things being kosher or not, but I used to have the same sort of opinion about Clean my mac.app but I have been using it occasionally over the last several months and I must admit I'm quite impressed, but the user must have a rough idea of what they are doing.
