Is it feasible to unroot a tool?
This actually depends. What phone are you making use of and also just how did you root it?
As an example : some phones have a very easy "one click" origin method to root your phone. They usually have a reverse very easy "one click" unroot method. An instance of this is EasyRoot for Droid.
When it comes to doing it using a manufacturing facility reset, that's not always sufficient. Manufacturing facility resets generally (constantly?) clean just the customer dividings such as
/data without touching the system dividing, where
su and also various other proof of rooting is most likely to continue to be. Re - blinking the ROM needs to suffice however, although some tools have flash counters that might additionally be examined if you send in your phone for service warranty objectives.