When you’ve got 15 spare minutes and the color is where you want it, put on a pair of rubber gloves and get out the blender. After you rinse the chiles, chop the stem off each (I use scissors), get rid of any bad spots, and drop them into the container of the machine. You can core them and clean out the seeds, but why bother? This stuff is going to be hot no matter what you do.
Pour in enough white vinegar to submerge the chiles, along with a handful of salt. Puree until quite smooth. Transfer the sauce to a pot and bring to a boil, stirring once or twice. Seriously: at no time during either of these steps do you want your nose or eyes anywhere near the fumes that waft from these vessels. Funnel the sauce into a clean jar or bottle and cool. Then cover with a cloth napkin and let the mixture sit at room temperature for three days, undisturbed. Carefully pour off all but a thin layer of the vinegar (which true enthusiasts save for another use) and refrigerate.