It does not require very ...

It does not require very much  chlorine, but it must be continuous. As you well know there are numerous easy to manage methods, that vary by cost and availability in some areas.  The simplest is sodium hypochlorite (laundry bleach)  that can be purchased or  produced on site by electrolysis of salt solution, including solar source electricity. I once saw a bicycle  operated electricity generator.  Since it is a liquid, it is easy to meter in at a continuous rate. Calcium hypochlorite is stable and available, but a solid. Chlorinated isocyanurates that are often used for swimming pool disinfection, are also stable solids that  can also be used for drinking water-see WHO Guidelines. The isocyanurates are probably costly by comparison to NaOCl, but more stable. Keep in mind that the concentration x time (CT) determines the minimum dosage. For chlorine at pH 6 to 9 and at 10C, you can get 3 logs of virus removal with 1 mg/l for 4 minutes contact time. Less chlorine is need at warmer temperatures and longer contact times.