Our study focuses on identifying the causal effects of the most heavily used social media messaging app in the world—WhatsApp—on exposure to online rumors and its downstream effects on attitudes. WhatsApp, an encrypted messaging app that allows both one-to-one and group communications, is the leading social media platform in most Global South countries. We deploy a field experiment that addresses these WhatsApp-specific challenges in India and South Africa ahead of the 2024 general elections in both countries. We tackle misinformation exposure in two experimental interventions: (1) reducing exposure to \textit{multimedia} only and (2) reducing overall usage. First, in our Multimedia treatment arm, we replicate (Ventura et al 2023) by asking treated participants to turn off their automatic download of multimedia content---that is, images, videos, documents, and audio---received on WhatsApp and further incentivize them to not access any media during the four weeks. In doing so, we expect participants to not only spend less time viewing media on WhatsApp, but also to be more intentional about what they choose to see on the WhatsApp platform. Second, in our Time treatment arm, we implement a stronger intervention that more directly reduces WhatsApp usage by incentivizing participants to reduce their WhatsApp usage to up to 10 minutes per day for a period of four weeks.