What do you mean by 'clean'. Do you eant to remove unused/unwanted files or remove a suspected virus ?

I am not sure that there is concept of 'cleaning' a partition.

You can use variations of the find command to locate and delete files and / or directories.
for example:
find /path/to/directory -type f -atime +100  -exec rm -f {} \; 

will locate and delete all files which were last accessed more than 100 days ago. Obiviously, this needs to be used with care so that you don't delete something importatnt.

I am sure that others will give you more options.

On Sun, 2019-02-24 at 19:24 +0100, Andreas Aßmann wrote:
Can anybody tell me how I can clean my Fedora partitions, especially 
system partition?