Some of my friends threw a Mustachio Bashio (mustache themed party) at which all attendees were required to sport some sort of mustache.  While many of the men attempted to grow authentic facial hair in advance, the less hairy gents and most of the ladies were in need of assistance.  Of the hosts a couple of them used these and the remainder of the mustaches were similar to the spare jackets kept around at fancy restaurants just in case someone arrives without the proper attire.  I believe the invites did state "If you do not arrive with a mustache, one will be provided for you"!