'Nesh' is common usage in Sheffield, though not used with any regional prejudice in my experience. Lancashire retained its clog dancing tradition more widely and recently than Yorkshire (largely, I suspect, through stage connections) but clogs as such are not, I think, 'more related' to Lancashire; or the north-east, for that matter. The clog shop on Lady's Bridge in Sheffield is long gone, though.

As for 'clogdop', you should ask Pete Smith of Sheffield City Morris when he gets back from Australia. I think he was partly responsible for the 'medup' morris style, and it sounds rather up his street.