I really think you have two options (well 3)
1) Switch to salt
2) Switch to a automatic liquid CL dosing system.
3) Somehow get your wife to dump in a 1/2 gallon of bleach each day.
1 is going to be the easiest, but 3 should not be that much of an effort. Don't even both to test, just have her dump it in every day. We have a person watch our house when we go on vacation (well, she watches the dog really, but lives in the house). I have her dump a "green bottle" (Ita quart nagene jar) of 10% CL in the pool every day. My pool only seems to need a quart a day, not a half gallon, be we always come back to clear water.