Make sure that the water is as cold as your husband can comfortably drink when you ozonate it (it does not have to be ice-cold, but cold nonetheless). Ozonate it for about 15 minutes and then drink it all within a minute or two after that. The faster he drinks it, the better it is.
Maybe James can comment further when he has the chance.
Not a whole lot to add you covered it pretty good. The only thing to add is if using a diffuser keep it as close to the bottom as possible to allow more contact time for the ozone bubbles to react with the water.
Ear insufflation is also good for saturating the head area with ozone.