I'm not sure why you'd want to do that, considering that it's inefficient (it requires internet access, and it's capped by its speed), and you're rolling the dice on whether it's wiped or not. eg. if you have 100GB of free space to wipe, and the closest you can get to 100GB with your steam games is 95GB, then there's a 5% chance that your data would still be on the disk. Doing something like

   cat /dev/urandom > /path/to/mount/point/temp.bin && fysnc && rm /path/to/mount/point/temp.bin

is much more reliable and isn't dependent on your internet.