Well...
This won't work, since your account is flagged in the Valve/Steam database, and that is however server side.
But hell, if you're the owner of Valve/Steam and have the DB on your computer, well then deleting it might help...
But no way this is gonna work, it's just gona fuck up your computer installation.
Cause your changing it CLIENT side, and not SERVER side, where your account is stored in a databse, hacking the database might work, but not with this method.
PERIOD!
Andorenan.