Possibility to install ML directly from the hard disk? Does it possible to install Mountain Lion (clean install) without using USB key or DVD?

I'm currently running on SL, and I want install ML (I already have the dmg file).
If you boot into the Recovery HD (⌘ cmd + R or ⌥ alt/option then select Recovery), you can open Disk Utility and Erase the internal drive.

Then close Disk Utility and use the Reinstall option in OS X Utilities to reinstall OS X.