Purple pipe glue on acrylic tub
We are working on DD's house to get it ready to sell. In giving her tub a thorough clean, I noticed a purple drip/stain on her acrylic jet tub.
I asked if they knew what it was because none of my cleaners did squat. They said it was there from day one when they moved into the new house, and they were pretty sure it was where our plumber set down some pipes to dry and got the purple glue on the tub.
That was five years ago. Any suggestions to clean that off?