Hi,Speaking as someone who has the Ulster accent I've never said "cliddery ba' in my life! But having worked with people from Ballymena (and further North)it's perfectly believable. They have a lot of strange words up there. Many of them wonderfully descriptive.
I looked it up in my "dialect Heritage of North Ulster book" a wonderful little book put together by school kids the nearest it came to "clidder" was "clod" meaning to throw,
Slainte
alison