Which is best … CleanMyMac or OnyX? Both? Neither?

Do not install any third party app that claims to clean, protect, manage, boost performance, tec. These apps are not needed, use system resources while providing no benefit, and they may cause problems.

Don’t use any clean programs on your mac. It will do nothing and only make your mac slow. Please keep clear from any of this programs

OnyX can provide a benefit, but can also be dangerous if misused.

CleanMyMac is actively malicious and shouldn't be used under any circumstances.

(231472)

Clean My Mac is complete garbage.

ONYX can be useful, but if you're not well versed in UNIX utilities, you should avoid it. It is very powerful, but dangerous in the wrong hands...

You may also want to look at this article:

Effective defenses against malware and ot… - Apple Community