Odour Control and Extermination in Sewage and Wastewater Pits

In our work to offer solutions to some rural and urban settlements using pits and suck-aways to collect and evacuate the sewage/wastewater and associated sludge, we have used and recommended "Chlorine-containing solutions" to control/exterminate odour which is instant in action, very efficient and cheaper within our known reachable solutions. In this type of set-ups (using pits and suck-aways), are there other solutions that are better in odour control/extermination? Thanks Justin