You will kill any boss quickly and easily on both NG and NG+.
Note that you MUST have the sword as your active weapon before applying the cheat.
You can get +30 as well by replacing the "14" (last line) for 1E, but higher values such as +99 or +1000
won't work, the sword will be even weaker than before. +40 or +50 may work but I haven't tested it.