Once you use this, you can reset the password to anything you want. Please keep in mind you have to physically power down the unit, connect a console, then power up. Then hit "Break" within your terminal program and follow the instructions. Pretty simple, actually.
Answers & Comments
No need to flatten the configuration and reconfigure:
http://www.cisco.com/en/US/docs/security/asa/asa71/configuration/guide/trouble.html#wp1058131
Once you use this, you can reset the password to anything you want. Please keep in mind you have to physically power down the unit, connect a console, then power up. Then hit "Break" within your terminal program and follow the instructions. Pretty simple, actually.
Good luck!