Cool idea! I also know sachet water from Ghana - a quick google search suggests it is common in Sierra Leone and Liberia as well, although it'd be helpful if someone with firsthand knowledge could comment. The only risk I could see is that people may hesitate to buy water with ebola symbols on it unless the messaging is extremely clear for all. Regardless, I think the idea of using existing supply chains that already reach remote areas to distribute information has huge potential.
This is very inspiring! It reveals the importance of considering the informal caretakers who are also highly vulnerable in addition to more formal health care workers. What other commonly available materials besides trash bags could potentially be used to help protect these people?