It actually worked like they said it would. Usually the bolt head wasn't completely rounded off, so I don't know how it would work for you, but it's worth buying one. They're handy little suckers. We would generally toss the factory drain plug on the customer's first visit if we could talk them into it. I actually had a dedicated set of sockets and two GM plugs to show to them. Make sure your new plug actually fits a wrench found on this planet and is not a direct OEM replacement.
I might recommend that, instead of vise grips, you try a tool made to turn round things. Our pit man had a small pipe wrench and a good sized cheater bar for really bad ones. Also, I can't really tell from the picture, but if those craftsman jobbies are the ones you whang on with a hammer and then break a ratchet trying to turn, I'd stay away from them. I suspect technology has improved since the 1430s, when my old boss bought the tools we had in the pit, but back in the dark ages we had this wacky bolt remover thing that sold a number of new oil pans.
And whatever you do, never try to take out an odd-sized oil plug with a crescent wrench. Oh the horror.