I am doing some long overdue cleaning on my computer and have a couple of questions.

1 - Lost+found - I see multiple gig of space being used by the lost+found hidden directories. One partion has been emptied, but still shows 7.5 g used. How can I (or should I?) "empty" the .lost+found dirs? The trash files have been emptied, but still the mystery files.

2 - .Trash - The trash has been emptied, but it is still holding data. Example of 5.9 g on one.

3 - Multiple trash folders - .trash-0 and .trash-1000 both. Is this an issue, can it be cleaned up?

I have found BleachBit and have started to use it periodically.

Any help, information and correction is welcome. Thank you.