Someone sitting next to me at a tacqueria doused their taco with this stuff, just like regular piquante, took a bite, and then paid the price for the next twenty minutes.  Learning from his misfortune, I took a few tinefulls (on the tip of a fork) on my taco . . . not even a full drop as recommended.  Just the perfect amount.  Two hours later, I still feel a nice lingering heat.