Highly uncomfortable and undesirable, but often essential when you're in a rush to get somewhere, and remember you haven't shaved that day.
"Forgot I had that job interview this morning, woke up late and had to rush out of the house."
"So what's with the chin?"
"Ah, I had to resort to dry shaving"
"Fancy a night out? If we're quick we can catch the metro/subway/train/bus in for cheap?"
"Yeah I'm game, just let me grab a dry shave"