I would suggest flashing a ROOTED stock image through Odin. If you were running CleanRom then you obviously have a unlocked bootloader as well. You'll need to re-lock that if you want it to be completely back to stock. I don't know how much you know, (obviously you know some or else you wouldn't have been running Clean Rom in the first place) but I'm just gonna lay it out step by step anyways just in case.
1) Go here: and
[HOWTO] [ROOT] [ODIN] No Tripping Flash Counter - Root + [TWRP] - Updated 05.25.2013 - xda-developers and download the VRBMB1 Odin flashable rooted stock image (it's the very first link), or you can grab the next link down which is similar image only with a FULL WIPE. Meaning you will lose everything on the phone. I would go with that personally, especially if your planning on giving the phone to someone else.
2)Extract the root66_VZW_I535VRBLK1.tar.md5 from the 7z file you downloaded. Make sure you have your phones drivers installed on your Windows computer and Odin installed. Also, make sure you don't have Samsung Kies running in the background.
3)Boot your phone into Download mode ( by holding down volume down+Home+power, then volume up to continue when the warning appears), and plug it into your computer. When you plug it in you should see the little COM box in Odin light up blue and it will tell you it's connected in the message box by saying "Added!" Flash The root66_VZW_I535VRBLK1.tar.md5 in the PDA slot in Odin. All you do is click the PDA button and browse to wherever you put the tar file, click on it and let it load. Also, make sure that the the Auto Reboot and F reset time options checked (they should be automatically) Once it's loaded flash it by hitting Start.
Make sure you DO NOT unplug your phone while it is flashing. Also, these factory images take a few to flash (usually 5-10 minutes) so be patient. Go grab a cup of coffee or something.
4)When it's done it should automatically reboot, and it will say in the message box 1 succeeded 0 failed. You can unplug now.
Now you will be completely back to stock, including locked bootloader and stock recovery image. The only difference is you will have root still. Now if you wanna get rid of root just go into the SuperSU app and click unroot. It will un-install the SuperSU app and binaries and you will be on the stock rom. This also will not trip the flash counter. But if you already have a flash count then you can use Chainfire's Triangle away app to reset it before clicking unroot.
Now your all done and the phone should be completely stock and ready for whoever.
I tried to make this as simple as I possibly could.
Hope this worked for you!! If you need more help just ask.