This technique is one that we use at Revelation Life - making murals out of mud. It's something I came across a while ago from this guy, but hadn't been able to try out until we lived here in Uganda.
Many people are a bit nervous when you ask if you can paint a health message on the side of their house and understandably so. But these mud stencils disappear after about three months, which is just right as most advertising has a half life of a couple of weeks. Added to that, they are free and even make use of old x-rays for the stencil.
I think they would work really well just about anywhere as they even last quite a while in the 'power shower' rainy season here. Why not give it a go?
