I have tried previously to "iron out" the inside of a neck by repeated sizing and such. All it did was give me a sore arm, a bunch of busted cases, and a reason to buy an annealer from working brass too hard.
The ONLY way I personally found to do it reliably was with a custom tool I made for a Redding Type S bushing die. The big screw which holds the bushing in place, I made a custom one with a ball expander on it, which I turned to an exact diameter. Send the brass into the die, press the ball expander in, back it out, the remove brass from die.
It was VERY sensitive to brass thickness, for obvious reasons. Again, it was an exercise in "what can be done". The original point of the experiment was to try and align badly (and I mean badly) out of round brass.
Yes it works, no don't do it.