In fact this used to be pretty much the only use for olive oil in the UK - before the mid-1950s, 'continental' cookery was unusual and olive oil was generally unavailable except through a pharmacist as an ear cleaner. http://www.historic-uk.com/CultureUK/Food-in-Britain-in-the-...
It does have some anti-microbial action but it's known that the glycosinolates (found in onion family but also many other vegetables) have definitive antibacterial properties.
See eg http://www.uhs.nhs.uk/ourservices/ear,noseandthroat/audiolog... (for a non-woo, non-commercial reference).
In fact this used to be pretty much the only use for olive oil in the UK - before the mid-1950s, 'continental' cookery was unusual and olive oil was generally unavailable except through a pharmacist as an ear cleaner. http://www.historic-uk.com/CultureUK/Food-in-Britain-in-the-...