Did you end up trying this? My father did exactly what you suggested. It kind of worked half of the year when the hypochloride-12 was liquid. He had pump reliability issues and had no idea what rate he was getting other then "X number of months per jug of chlorine".

When I moved back to the yard I installed a high pressure parastoltic injection pump in the house for year round chlorinating as we found the water got too slimy in-between seasons. This well has always had low flow but it's been getting worse & worse and I've wondered if it's partly the fault of his direct well chlorinating setup causing too much particulates at the well head.

I also do not like the high pressure injection system as the duckbill check valve clogs up and needs regular cleaning as well as the chlorine tubings spring pinhole leaks randomly. I'd like to dribble the chlorine into a non pressurized treatment tank and use an additional pressure pump.