I get your point, but probably not 100% extra profit. I don’t know acht they do now, maybe just toss down the drain the excess Catholyte. Still, collection containers and employee effort to maintain stock and process shipments is still ‘cost.’ Call it 90% added profit - a pure guess.
I’m guessing the shelf life is longer than Hydrolyte? NaOH in NaCl solution should be fairly stable to my knowledge.