Securely erasing free space on OS X
 

Hi all hopefully someone will be able to help me here.

I am looking for a tool for OS X that will allow me to securely erase free space on my laptop. Ideally it should do at least Gutmann and DoD as a plus creating my own write patters would be great. The cheaper the better ;)

The reasoning for this is, even though OS X built in secure trash deletion is good, it is too slow on large files, So I would rather erase ~50Gb of free space once a week than erase the trash daily with what may be 2-3 Gb of data.

For comparisons sake I am thinking along the lines of eraser for windows but with or with out the additional file wiping.