Removing tremolo slashes

I wanted to remove tremolo slashes from all notes in a passage of twelve bars or so and found that I could do so only one note at a time, in engrave mode, though I can add the slashes to a whole selected passage with one click in write mode. The removal process involved (in my instance) a long cursor movement being made over 40 times. Is there a good reason that the tremolandi can’t be both added and removed in write mode as a batch operation?

In write mode on the tremolo pane, there is one quarter note without tremolo. Select all your notes and press that one.