Originally Posted by JoNex
Hey, does this procedure recover the Nexus S to stock factory settings?
Yes, once you install v2.3.6 it will be like doing a factory reset to wipe the phone. ClockWorkMod recovery allows you to install a lower OS version, that's all. Once you have CWM installed, use it to wipe the Dalvik cache as well as data and cache. Then run the stock v2.3.6 update and it wipes ClockWorkMod and replaces it with the stock recovery. You then lock the bootloader and it's like it was never touched.
Just make sure you download and flash the correct firmware version for your model and you should be fine.