Based on our record, CleanMyPC seems to be more popular. It has been mentiond 2 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
The CleanMyPC app scrubs the relevant registry when it uninstalls other apps. But your prescribed step 3 (scanning registry for "waterfox" after uninstallation & restart) did yield an escaped entry with "waterfox" in the entry (path/address), so I deleted it before restarting and installing. Source: over 2 years ago
CleanMyPC (to note that they are no longer maintaining nor updating this app). - Source: dev.to / over 2 years ago
CCleaner - CCleaner cleans, speeds up and frees up space on business endpoints.
Avast Cleanup - Next generation tuneup and cleanup for your PC
AppCleaner - AppCleaner is a small application which allows you to thoroughly uninstall unwanted apps. Installing an application distributes many files throughout your System using space of your Hard Drive unnecessarily.
Wise Disk Cleaner - Clean junks of Browsers, remove junk and useless files of Windows and Defragment your disk. Wise Disk Cleaner can delete these unnecessary files on your hard disk to free up disk space and make your computer run faster.
CleanMyMac X - Clean, protect and speed up your Mac
SDelete - Securely overwrite your sensitive files and cleanse your free space of previously deleted files using this DoD-compliant secure delete program.