Yes you could, just need to control the power to the elements, have a high temp sensor, and maybe a little display to make it all official
im planning on doing it with my toaster oven, but not yet as im only using it destructively to remove parts not put them on and so I don't care if the temperature is as 350 or 400 or 450, just so long as the solder melts
In a reflow oven the temperature is quite important, as well as following a proper temperature curve which is pretty easy once your controlling the heating element