The question:
"cleanmymac x any good" ?
The answer:
Not really...
The problem is most folks would only use that application (or something similar) to perform cleaning. That is certainly not enough.
From my perspective, the act/task of cleaning occurs everywhere. And how one deals with it in one respect permeates over to cleaning anything. I am a cleaning"nut", no matter what that entails. When I clean our cars (and I do it often when the weather is nice), I definitely make a concerted effort to clean everything, both inside and outside (good exercise, too). When I clean our townhome, bathrooms, other household chores, etc, that same attitude and effort is there. Cleaning and maintenance are in my DNA. So that same attitude carries over to keeping my Macs lean, mean, and clean (I've actually been doing it since my Apple IIE days). And because it is in my DNA, it is neither a burden nor that time consuming. In fact, it is actually quite easy. The old expression "apply some elbow grease" applies here, and I follow that.
As it is, I am actually doing cleaning just about every day, whether it is in our place, or with my Macs. I don't mind at all, and I actually feel better doing it. For my Macs (my Mac Mini primarily), I am always permanently removing deleted EMails. It is real simple: delete EMails, then navigate to the Deleted folder in Thunderbird (my EMail client), right click on that folder, click on the first deleted message and click Command-A (Select All), select "Empty Deleted" from the ensuing menu, and viola, it's done. Takes all but 5 seconds. As James Whitmore said in "The Shawshank Redemption", Easy-peasy, Japaneasy. Yes, simple and quick.
Also, when I download a new version of an application, I make sure to delete the prior version from a folder I maintain called "Useful Applications" (for a couple of them, I keep the prior version, so I get rid of the one before it). I've also mentioned the use of AppCleaner and EasyFind for completely removing both an application and all its "pieces". Does not take long at all.
I suspect that by doing all that frequently (daily in some cases, as I mentioned), by the time I perform my weekly cleaning and maintenance tasks on Saturdays using Onyx and TechTool Pro, there might not be very much to clean and/or maintain. But again, so what. I want my Macs as lean, mean, and clean as possible. And while those tasks are going on, I am not just "sitting on my thumbs". I am actually cleaning our place. Multitasking, a valuable concept!
So, at least for me, the benefits of my cleaning DNA are 1) a happier life, 2) for a number of such tasks, getting exercise (which is always good), and 3) for my Macs, rarely, if ever, having an issue/problem.
I realize my way is not for everyone, nor am I preaching that people need to do it. Whatever works for oneself is fine. I am just relaying my thoughts, perspective, etc. on this. I know this cleaning and maintenance "business", at least for Macs, has been discussed MANY, MANY times in the past, and suspect it will continue. That's actually good, but it is important that one does not get "bashed" for their practices. Respect needs to be there.