This is NOT for how to get your shine back, but how to preserve it. However, it may not be a good solution, because it involves hazardous material. But here it is anyway.
First, find someone with a 80's vintage Porsche 911SC/Carerra, and ask if you have their used antifreeze mixture (from the overflow tank or when they are flushing). The good part is that you don't need much. Get that, and you can diluted with some distilled water, maybe 3 to 1 ratio. Most have silicone in it already, but you can spray a little WD40 in it if you want.
It must be from that 911 vintage, otherwise, you're wasting your time.
This used antifreeze is special, because it has been exposed to the special aluminum alloy engine block and head that were used in those years. So, it serves as a metal preservative.
Then all you have to do is to smear this onto your shiny prop with a shop rag. Wear gloves and make sure your pets or children are not around to ingest it. Viola, your prop will remain shiny for awhile.
Finally, don't get it into the lake or public drainage.
Staying with the 80's theme, got too much time on my hands.