How To Get A Gross Shower Clean - Amazing!!

When I moved into my old house, its previous occupants had been evicted. The house was a disaster and looked as though the previous folks never cleaned. I love to clean and I am kinda OCD, so I whipped the house into shape pretty quickly, but for one thing: the acrylic one-piece bathtub stalls. The layers of soap scum were incredible. You could scrape it off with a fingernail. Ick. No matter what I tried I could not get the bathtubs and their surrounds to look and stay clean.