Debbie, you've made a good decision about a problem roo. I've owned/encountered enough gentlemen roos to have little tolerance for any unmannerly ones. You don't want to wait until they've maimed or bloodied any other bird, animal, or child that you love before you decide to put them out of your/their misery.
You were considerate not to try to re-home him anywhere else. Some folks lead with their hearts & not their heads and will give any aggressive animal a chance to live -- and hurt something else.
But for anyone who hasn't yet butchered chickens for meat, I would advise having someone else do the beheading, if the chop block is the decision. It can take practice & the right tool to do the job neatly & quickly. It would also add to the owner's guilt, if they were already sad about having to dispatch a mean roo, if they couldn't finish it with one stroke.
I'd also be careful giving/selling aggressive roos for meat to anyone I didn't know personally. I wouldn't mind if they were going to eat it themselves, but sometimes folks will use roos, esp. feisty ones, to train/bait fighting cocks or fighting dogs.
If you lived near me I'd be glad to help you by dispatching your roo for you, and help you dig a deep hole in which to plant him if you wanted.
I'm also interested in the ether/automotive starter fluid method of home euthanasia. I cannot afford any vet fees for euthanizing a chicken, but I would like to learn a more gentle method if ever I have a dear sick/injured hen.
I'm not yet to the place where I could eat the old girls, though I understand & respect those who do.