This simple plugin does one thing only: removes the old spray cache files that build up over time in the downloads/ folder. It does this every time a level is loaded so you don't have to worry about the folder getting too large.
By default, it deletes only the files that have not been accessed in over 7 days.
You can control this using the the sm_spraycachelifetime console variable (defualt value is 7).
Threaded Mode