I do not have such a wrench, buying one seems to be excessive for just
one stupid task.

make one. An old automotive timing belt works great. Pull it tight around
the item to be turned, clamp it with ends of teeth of vise-grip and twist in
direction of the rounded top jaw. I save old belts for all kinds of jobs.
Screwing it to a 2x4 also works well, just round off the top where it
presses the object, but it's not adjustable.
--
Stupendous Man,
Defender of Freedom, Advocate of Liberty