I’ve heard they do more harm then good. Is this the case, and are there any free ones that stack up to the likes of System Mechanic?
some said it’s the snake oil of computer industry 88)
CCleaner is among the safe ones
CCleaner and the free one from Auslogics are both good and safe. Auslogics has an advanced mode that should only be used by experts. The standard mode is perfectly safe. A good registry cleaner can find and removes traces left behind after uninstalling things and can increase performance, especially startup times, noticeably if they are used after a period of not using one.