I used to live in St Croix and managed a bar there - and the Coca-Cola was more expensive than the Cruzan we mixed with it.
Got a bottle from my distributor there once that had a dead lizard floating in the sealed bottle. Wish I'd kept it.
It's hard to tell what the sediment might be without seeing it, but my first guess would be lizard poop
Actually there is a 20 year old aged rum that I remember called Ron Metusalem - Bahamian, I think. It's unbelievable, tastes like a fine cognac

Probably hard to find locally, tho -