I can answer that :) I have a Bain Ultra acrylic air-jetted tub. They said to use cleaners that aren't abrasive. Well that's much easier said than done as you've found out. So the only thing I could use was "Gel Gloss". I find it at Lowes and it's awesome stuff and keeps your tub cleaner longer. Problem is (for me) all the steps. You spray it on, let it sit, wipe clean and then buff to a shine with a clean cloth. No water needed. It's an ordeal. If you don't have back problems it might be a piece of cake (g) I've been just using a soapy wash cloth and occasionally , Scrubbing Bubbles :o Can't help it. That stuff is amazing! But I gotta stop it. So earlier this week I called Bain Ultra and told them that I can't find the word "nonabrasive" and " safe for acrylic". They finally acknowledged that the labels don't always say it's safe so she gave me a list of some safe products:
Fantasic
Oxy Power
Windex
Soft Scrub Lemon (and she accentuated LEMON)
Mr Clean All Purpose
Lysol Disenfect

Hope this helps :)
Monica

I always used white vinegar and water when I cleaned for a living.

I asked Bain Ultra about white vinegar. Someone had suggested water/white vinegar and a teaspoon of dish washing detergent. They said that was fine. I wasn't impressed with the results on my acrylic tub.