[Q] Painless root / Unroot ? [Noob Q] topic

Guys i need to know if its possible to root the phone and unroot / take it back to warranty condition WITHOUT reflashing and unlocking bootloader.

http://www.youtube.com/watch?v=ZCChDxc2_HE heres what i've found about unroot... but i am not sure in this method will it completely remove root binary and take phone back to warranty:eek:N mode ?