OnyX is an excellent (and free!) program that I occasionally use with my machines but it is not something I feel the need to do regularly. MacOS is designed to keep itself running fairly smoothly and consistently, it has its own maintenance scripts which run unobtrusively in the background; no need for the user to be tinkering with, "cleaning" and "maintaining" the machine all the time. The days when we used Disk Utility to run "repair permissions" are long gone with more recent versions of the OS. (I just realized that I never got around to installing or using OnyX on this machine, which I bought new in December 2018, and I have not experienced any issues which would nudge me into doing so.) One program that is highly praised and recommended is MalwareBytes, and it, too, is free after the initial trial period is up; one simply ignores the "update" message and it converts to the free version. When one runs a scan on it if there are any issues, any unpleasant items in your computer that shouldn't be there, MalwareBytes will inform you and then take care of the problem.
A-M-K, we've had discussions before about Mac Mechanic, and I still suspect that it has been causing more issues than it has been resolving in your machine. I strongly recommend that you remove it from your MBP, and that you definitely refrain from installing it in a new computer! A Mac is not a Windows machine, there is absolutely no need to run through any sort of "cleaning" routine every time you want to use your computer!