Like this idea, as it's closer to a systemic approach to treating the problem at the source. Seems like less of a bandaid than bed nets. I wonder how effective this would be in conjunction with vaccines.
It's also worth considering that vaccines can't rip, get lost, or be installed incorrectly. It also protects the user no matter where they go-- they don't have to stay in bed to be protected.
Even if slightly more expensive, vaccines seem like they might be more convenient for the people who need protection from malaria.
I wonder though if there are other major mosquito-borne diseases that bed nets protect from besides malaria. If there are, then a combination of nets+vaccine seems best.
Baking soda may not always be readily accessible, but where it is adding about a teaspoon of baking soda to a liter of water also dramatically cuts down bean cooking time from dry. Possible to cook chickpeas in ~45 mins to an hour, instead of 2 or 3 (in my experience), and you don't have to remember as far ahead of time as with soaking.
Otherwise, I feel like a radio or sms campaign in areas with high access to those resources would be a pretty cheap way to disseminate this info.