[Richard]

I would go another route. Remove the ceiling, if stuck use spray 3M adhesive remover to gently get it to release. Get it down and clean up any obvious globs, but not necessary clean both mating surfaces to brand new. Just get the high points out of the way. Spray them both with 3M high tack trim adhesive, the stuff auto folks use for roof liner. Get a helper for putting it back up cause once it sticks, you are not moving it. No shower rods are braces needed. But it better be where you want it when you stick it.