There are a lot of useless apps in the App Store. "CleanMyDrive" is among them. The database files it claims to "clean" exist to enhance a Mac's performance. Deleting them will degrade performance, and require them to be rebuilt. Other tasks are more easily and safely accomplished by using the user interface tools every Mac already includes.
If you simply want to waste time, there are plenty of games to choose from.
When discussing any Mac related concern you should purge the word "clean" from your lexicon. It's misleading in that it implies neglecting a Mac will cause it to somehow become "unclean", and after all who wants a filthy Mac. The emotional connotation results in many Mac users represented on this site to relate tales of misery after using garbage "cleaning" apps. Avoid them as you would a social disease.
Macs are designed to be neglected when they're not being used, and work best if you simply leave them to work as they're designed to work - as the productivity, communications, and / or entertainment appliance you presumably concluded it was when you made that very wise purchase decision.