"I never worked out what 'the other purpose' was."
Some people are known to wash their clothes in the tub and then try and dry them with the hotel hairdryer (which invariably burns them out).
I did hear of some tourist to Finland from an Asian country who felt it was cold so used the in-room hairdryer as an extra warm air blower (left on all night, unit overheated and blew some fuses). Maintenance people in hotels don't like 'em (hmm both dryers and many visitors).