full cleaning

Hello.
I red, in https://doc.ubuntu-fr.org/bleachbit , that, for a complete cleaning, it's necessary to run BleachBit with the command line 'gksudo bleachbit' in a Terminal.
If we run bleachBit, the paper says, with its icon (brush only), the files owned by root will not be erased.
And, if we run it with the other Icon (BleachBit (as root)), only the files owned by root will be erased.

Is this true ?.

I shall run BleachBit 4.4.2. I use Ubuntu 22.04.01.