How good is Cyber Scrub????

Lots of claims are made regarding cyber scrub,erasing as opposed to deleting all unrequired files.......having once been hacked and bank accounts emptied(bank sorted problem with four days even to issue of new cards),I installed cyber scrub to ensure all data deleted would then be erased.

To test whether this was fact I then used a simple recovery programme which did retrieve files which in theory had been ERASED by Cyber Scrub....so how good is it?
Most Geeks will tell you that with modern hard drives one pass erasure is more than sufficient with 3 passes being over kill....if that is the case why was I able to recover preciously deleted files which had been subjected to cyber scrub erasure?:confused