srm -rlvz to delete a directory, like ‘srm -rlvz DIRNAME’ (r) recursively (dir and all it's contents), (l) overwrites only 2x not default 38x, (z) then with zeros, and shows progress (v verbose).

The standard way is just

srm -f myfile.txt

(f is a single pass)

or

srm -r -v myfolder/