I'm dealing with a few sorrels myself. The small type which covers and the big ones that never die.
Repeatedly cutting them has taken care of the most persistent ones in the main beds, digging them out with a trench shovel and repeatedly digging out the smaller offshoots with a hori hori knife i carry in a builders
pouch has done that.
But in the wetter spots the big ones seem eternal. I keep cutting them down with a zeiss. Busy growing Russian comfrey over them now. Dumping
straw on them all the time helps a bit too.
But when i turn my back they're back again. Can't say that i really, really care. Usually i go on a rampage against a plant because i can't control them, in fact i am the problem, i've realised over the years going on campaigns against
native plants. I tried to kill all yarrows until i realized it cures my
trees, my wild violets out of fear they'd take over... Madman style. I try to consider them free mulch now, and those roots might have a good function, leaving plugs rotting down in the soil, opening it up.
It sure looks messy though, but visitors i can't take them seriously any more since my neighbor lady who never grew anything more then the
rose she spends a hundered bucks a year on ciding it said all i grow is weeds and her husband visiting later saying i do
permaculture all wrong, i have to mix everything up much more.
But my
project is with the farmer and keeps expanding and expanding, so i'd better not care too much, when it would be limited i'd care probably.
Trying wintercereals rye has helped a bit too. Parsnips have the same function a bit and are edible and self seeding where i am, daikon, black radishes, make these crazy roots, could have the same function...
Good luck!