venue management

Is there a straightforward way of removing all venues?
I have tidied up a long list of current and past events (musician’s tour calendar since 2010) and some venue were listed incorrectly or duplicated. I have exported the CSV and manually corrected where possible and am now about to re-upload the entire list of gigs. Hoping that the venues will also recreate a fresh list after removing all the existing ones. However there are now 18 tabs of venues, each one with “0” associated gigs of course, but no means to simply clear the deck and start again.
Any suggestions?