In my opinion, the best cleaner for you Mac, is macOS. It runs daily, weekly, and monthly, routine maintenance scripts that will help keep your Mac running smoothly. However, some of the things you will need to do to be safe on the web will help.
Depending on which version of macOS you are running will matter as well. The newer the OS, the safer your Mac will be, currently 10.14 is where it's at.
Also, whichever browser you choose to use to surf the web, you should also add a content blocker, and an ad blocker.
As with all tools used by man, they require your care and safety as well. That means practice safe surfing, and security of your data, and last but not least backup, backup, backup.