Hey Moose , take it from someone who knows first hand.Your worries about uncontroled spreading are very real.Tried to clean out a sizeable patch on my grandmother's land and that stuff is thick and hearty.Even when we had cleared it all out and dug up the root system we saw there , they grew back stronger the next year.It was as if we had pruned it and set it to growing at an excelerated rate.Bout the only way to get it gone is with controlled fire burning deep.Maybe you could grow them in boxes like a raised garden and control them that way , but you would need a pretty big box.
Commercial fishermen help feed the world.