Well, I don't trust American manuals lol
I expect if there was a zombie infection, our government would just throw a vacuum bomb at them. It would destroy them all and leave no radiation behind, like a nuke, but better, leaves the land liveable.
Best personal weapon against zombies, in my opinion, is a flame thrower. Burn them all up in seconds
Like an LPO-50
Yes, it is from the 50s, but old does not mean bad, as the PPSh keeps on proving to this day.
More modern 'reactive' flame throwers like "Rys" ("Bobcat") are also good
But nothing creates a wall of flame like that LPO-50, that's for sure. They knew how to make weapons back in those years...