It does not require daily cleaning to keep buckets mosquito free.
We have a mosquito bucket to collect larvae to feed my Bettas, and the whole process of letting the water get aged enough to attract the bugs and for the eggs to hatch to larvae takes around a week. Mosquitoes need organic material in the water to host microorganisms for their larvae to feed on, so they don't lay in fresh water.
Every time a chicken drinks, microparticles (at least) of feed, dirt, bedding, and chicken dander/oils from grooming is deposited in the water. That's a lot of organic material. Most water sources already carry the algae and microbes ready to "bloom" in the right conditions. Yet it takes time for that bloom to happen.
If you scrub (not just dump, but scrub the walls of the bucket) once a week, you won't have mosquito larvae. If you only dump and refill every other day, you won't have mosquito larvae.
Our run water buckets are within 25ft of the Mosquito bucket, and we don't get larvae in the chicken waterers because we scrub them before refilling. Having a good stiff brush with a long handle makes the job easy and fast.
Putting bleach or vinegar in the water, with the potential reduction in drinking from taste, is more harmful than eating larvae (chickens eat bugs).
So, if you're determined to forgo maintenance you can just let them have some "snacks" when they drink.