I have replaced the inner ball & rubber inserts & springs in my 40+ year old Delta shower several
times in the past year. The changing outs only results in a week or so of the leaking stopping.

In looking inside the fixture with the ball out I see that the copper inside has turned green. Would
any particular brand of Naval Jelly be too strong to use? What would you recommend, assuming that
removing the corrosion inside there would help make a better seal between the fixture & the rubber &
the ball.