With DBAN, it's a matter of drivers being available, because DBAN is, in effect, its own OS. It's different with programs such as Eraser, because, if Windows can see the array as a drive, Eraser can work with it.
As you have already used the HP tool, it isn't clear to me what state your array is currently in. Nor do you say what you mean by 'not secure enough'. But, to take a guess, if the array still exists, is now empty of user files and is seen by Windows as a drive, a free space erase with Eraser should remove all traces of previously deleted user files. If there are areas of the physical disks that cannot be accessed by the Windows files system, Eraser will not touch those, but they shouldn't contain user data in any case.
I hope that helps. Without more information it is difficult know your precise requirements.
Hmm, if you are erasing the disks in your array then chances are the array can be broken down to its constituent disks and the disks themselves erased individually. That would be a bit more secure as then the disks will not be "randomly in sync" -- the disks have random data, but the data seems to correspond to each other which indicate that a disk erasure tool has been used.
Having said that, David is one who says that random data on the disk is incriminating enough. Ohwell.