"Ah my dear, he's just blowing smoke up your arse." Ick. Of course, this refers to an insincere compliment. A possible origin for this dates to the late 1700's when it was a common practise for doctors to try to resuscitate a drowning victim by ... you guess it .... blowing smoke, yes, there. Along waterways the equipment for such a procedure was hung at regular intervals and emergency workers were required to know the locations just as now they are required to know the location of the 'defib'. What I would like to know is who the genius was who decided it would be a helpful thing to do. Where DO these ideas come from?
Anyway, pretty useless treatment, and insincere compliments are pretty useless as well.