Troubleshooting

Cachet didn't find something I expected

It only checks known locations, lists items of 1 MB or more, and skips Apple's own folders.

Cachet only looks in the locations it knows: everything Cachet looks for.
An item is listed only when it uses at least 1 MB.
Folders in Caches and Logs whose names start with com.apple are never listed; macOS manages them.
Simulators, Docker, Time Machine and iPhone backups are shown under with a little help, not as items to clean.
Very large folders are measured for up to 30 seconds each, so the size of a huge one can be an underestimate.
Run View › Scan Again (⌘R) after installing or using something new.

If something big is missing that you think should be there, tell us; it helps us add it.