Power Tabs in Nairobi?

I recently moved to South Sudan with my family and we are almost finished with our house. We're in Nairobi for the time being because travel in SS was getting hard, but we're planning on going back in a few weeks.

My husband is almost finished doing the work on our house, and I made curtains for the windows before we left the States, but I would really like to treat the curtains with some kind of insecticide so they don't become a bed for mosquitoes in the rainy season. Lots of people have told me to look for Power Tabs, but I've tried chemists, hardware stores, regular old shops, and even three Nakumatts (Prestige, Junction and Mega) but everybody just tells me they don't have them and to try [fill in a place I've already tried]. Does anyone know where I can get this stuff?

Thanks!

Amy