RFC- Option to make invisible only the 2nd line of a 3 lines staff

Request: Select one (or more) specific line of the staves and make them invisible, but the Notes, rest and other musical elements on the selected line must remain visible.
I work with soloist concert castanets, and to reproduce the most used real "beats" (at least 6 different "toques/sounds"), I need a staff with 3 lines. The standard international notation represent the "beats" on a 2 line staff. In order for my score to be conform with the standard notation , I need to make the 2nd line invisible.
I have created ma own castanets instrument, which is able to simulate the natural sounds of the 6 "toques" .
More explanation on the attached document.