Here’s Cecil’s answer
A far better way to control your sneezes than blowing against shut nostrils is to control your respitory system. When you notice you’re taking in a big breath for your sneeze, just calm down and exhale slowly. It is more comfortable than the nostril-Valsalva and definetly more comfortable than propelling the contents of your nostrils and/or mouth across the room. Plus, it also seems safer. To me, it is also just as easy as sneezing, but perhaps Kung Fu and espescially Noi Gong helps me to control my body. Can you do it?