Advice on bending handlebars

[Deanhorsfall]

I have seen a few Youtube videos of people bending handlebars using a bench vise with some wooden inserts to protect the finish. I have a pile of handlebars to try this on but I thought I would ask if anyone had tried doing this at all? I know some bars are heat treated and I imagine that trying to bend those might not work out very well. I also imagined that maybe someone had built a jig to get a nicer result. What I was thinking was flaring out a set of drop bars and possibly bending a straight bar a tad back?

[Spaghetti Legs]

I have a Cinelli 64-40 that is slightly bent, maybe 5 degrees from horizontal on one side and I have absolutely wailed on that thing to try to straighten it without a budge. My bench vise is lightweight though.