I've been cycling for quite a while but only know about embrocation because of having to play Rugby when I was at school.
Had no idea that it could be related to bikes and haven't heard the term for probably about 30 years, so I'm not surprised that the guy in the shop hadn't heard of it.
He should, however, have been able to locate it on the shop website - assuming that @GaryM had spent a second or two explaining what it is.
This counts as a fail on the part of both people, I'm afraid.
Maybe @GaryM could tell us what his line of work is, so we can test his encyclopaedic knowledge on the subject