I was surprised to see this thread, I just harvested a quart of the Roselle calyces today. I plan on dehydrating them to use for tea but you can make jelly, jam. syrup and many other things with them.
They are tart and tangy. Commonly compared to cranberries in flavor. They also have good food value. I understand the leaves can be eaten as well but I've not tried them.
I left some of the older pods on the plants for seed and will gladly share seed later when they are ready if anyone is interested.
This is the common H. sabdariffa ~ Roselle that I grow.