One wide-nostriled whiff of this stuff and you'll know how it felt to be gassed in the trenches during World War I, so when it arrives, use the same technique as chemists do which is to waft it towards your nose. (If you want to play a very horrible practical joke on someone, ask them to smell it without telling them what it is).
Once it's inside your mouth, the vapors immediately travel up your nostrils and down your lungs and sting like hell. As you gasp for breath, it only serves to draw more vapors in, compounding the problem. My wife and kids, who refused to go near it, were in fits of laughter the first day I tried it. I'd periodically convulse at the dinner table as the fumes burned the lining of my respiratory system, unable to speak.
If you enjoy the burning sensation if spicy foods you will love this. Obviously horseradish/wasabi are a different kind of heat to a chili pepper, but it adds a bit of variety.
My favorite meal with this is to mix the sauce with sour cream, then serve over grilled steak, cherry tomatoes and arugula in warmed up French bread. Delicious! Don't forget the gas mask for your dining companions, and the video camera.