Default Odin back to stock. (Pro 8.4)

Hey guys, I found a used pro 8.4 on sale a good price, but is running cm11, my question is that is there a tread with the stock rom, factory image, original kernel, etc.
And I read that some users get stock on a loop after trying to Odin back to stock... is this something happens very often?
The main reason is that I wanna go back to stock to start fresh.