Problem with hiding stave...

So for the first few bars of a piece I have used a third stave (for a silently depressed cluster chord), however after a certain number of bars these notes end and so I don't need the third stave for the rest of the piece. The problem is that the 'hide empty bars' option under stye/general will also delete bars 7 and 8 on the second system. This is because these bars are technically 'empty' as I'm using picture (png) files for the clusters, with the rests hidden off the page. Ideally I would be able to make musescore recognise that bars 7 and 8 are not 'empty' and keep them visible.

I have unticked the 'visible' box for bars 9 and 10 as seen in the attached image. However, doing this for the rest of the score leaves the third bracket visible at the start of each measure, which I want to remove.

Please help! Thank you