Never done it before so this may not be correct but I’ve always been under the impression that the shocked area doesn’t extend out very far from the probe or whatever it’s called.
A low tech option I have used (takes several people) is to use a large net extended across an area of a pond. The person on each end slowly walk around the bank toward a third person who sits on the ground at the waters edge with chest waders on. The ground person pulls up the bottom of the net sort of like a purse seine and starts collecting up fish by hand and throwing back the bycatch.
No idea how much a net like that would cost or where you’d buy one. The one we were using had to have been 100’ long and 6’ wide, maybe 8’ I can’t remember, it was 25 yrs ago
edit…look up seining fish in a pond on YT and a bunch of videos come up showing different ways to do it