how to hide bars that are not empty

how do I hide bars that are not empty, but that I still want in the score

I have a trombone part where it would be good for the player to see what is going on at other parts, at one spot in the piece but not any other. I already know about the "hide when empty" feature.

I have a workaround for this, but Im just wondering how you guys deal with this.

cheers!