Nothing will "rejuvenate" a shower base unless it is a solid surface like Corian. Then it can be sanded. But an old yucky acrylic base means that the coating is worn off, it's lived it's lifetime, and it's time to redo it entirely. I'm really surprised that you got 20 years out of it!

Hi hollysprings,

The company who manufacturers it Fiat differs and said it can be made to look close to "new". So, I think the manufacturer of the product would know more then you do!

Or the manufacture of the product lies to make it look better.

If it is dirty and won't come clean, try a magic eraser. They really are magic for this type of thing.

If it is worn eg the surface is actually deteriorated, then nothing is going to bring it back.

I would believe Holly and all of her years of experience in the industry before I would believe the manufacturer of a product.

Just checked on Amazon and they sell that cleaner there. It is Prime eligible if you are a prime member - you could have it free shipping in a couple of days.

You can have somebody come in and paint it.

Here is a link that might be useful: tub reglazing

Rustoleum has a paint kit.

Here is a link that might be useful: Rustoleum

Once the gloss is gone off of the fiberglass or acrylic, it's done for. Phosphoric acid (the main ingredient in the cleaner you are thinking of) will only remove hard water deposits or soap scum. It won't do a thing for a worn out pan. And while you can have it "refinished", that too is a short term solution. Most refinishing jobs look OK for a few months and then you start having issues with them peeling or scratching. And you are still left with an older degraded plastic pan. The only long term solution is to start planning for replacement.

Plus, take a look at the MSDS sheet on that cleaner. It's classed as a pro product for a reason. If you do end up ordering it and trying it, please wear the rubber gloves, eye protection, and have good ventilation available. Using that in a small enclosed environment like a shower stall is a recipe for a trip to the emergency room!

Here is a link that might be useful: MSDS

Thanks for the comments; I having a tile guy come and get his opinion. I hate to replace the shower pan since there is no cracks or damage; only that it is dull looking and not glossy. It does have some minor marks on it but it not noticable unless you go do on your knees and really look at it close.