This may possibly be the most amazing control in the history of controls. Found by a friend on a hotel air conditioner.
There are clearly only two options, blow hard or blow harder. Otherwise, just stop.
Of course, the usual method for designing an air speed control is a range from Low to High, communicated either with words or a graphic spectrum, plus Off. Also, “more” is typically clockwise to the right and “less” is ccw to the left.
But this control shows the danger when you try to use colloquial English terms for interface controls. Great theory, but proceed with caution.