@farmerman,
I really cleared mines in 1970: once, because of the widening of the traffic separation area German Bight, this with our whole squadron.
Then the route for the then new ferry route Harwich-Hamburg. This was really "criminal", because the area was still totally uncleared, we only did it with three boats and under time pressure. (The buoy tender was already waiting.)
[We had had a red book, a loose-leaf collection, for the "mine risk areas". Changed every week, becoming smaller and smaller.]
From the early 1970's onwards, minesweeping chanced totally. (My boat was the guinea pig for various "new stuff" to be tested, but from 1974 onward my reserve unit became the landing craft squadron.)
But classical minesweeping is still done against moored mines, using towed wire cutters to cut the anchors of mines can be conducted.