I keep all my guys in 1ish gallons - don't sweat that too much!
In 1 gallons though, they need at least 2 wc's a week, or else the ammonia gets to a level that could really make them sick.
Do you have anyone that could do a sort of simplified wc? I would get several gallons of water all conditioned up, and ready to go, and simply tell the person to remove about 1/2 or 2/3, with a cup, or a turkey baster (So cheap, so brilliant for fish care), and then slowly pour in the pre-conditioned water. So they don't have to cup the fish, or rinse anything out. Just remove and replace.
The tricky thing there is keeping the temps from fluctuating too wildly, assuming you have em heated. Maybe they could microwave the water for like 2 seconds first?