Yeah most sharks piss through their epidermis when they die, that's why when you catch and eat them you wanna gut them straight away.
That's a myth. No animal piss through their skin alive or dying/dead.
Shark kidneys filter nitrogenous waste (mostly urea) from the blood, which is then expelled as urine. Sharks also retain high levels of urea in their blood and tissues to maintain osmotic balance with seawater, but this isn’t excreted through the skin. Their skin is not permeable to urine or other waste because of their tough dermal denticles.
When a shark dies, its bodily functions cease, including urination. There’s no mechanism for urine or any fluid to be actively excreted through the epidermis post-mortem.
However, as the body decomposes, fluids (including blood, bodily fluids, or retained urea) may leak from orifices or damaged tissues due to breakdown, not because the skin is "excreting" them.
Sharks’ high urea content, which can make their flesh smell like ammonia after death if not processed properly
Here are a few tips to make shark / flake near as good as any fish.
1- Smaller sharks are generally better to eat around the 1.5 M mark or less. Some species are better than others (Mako is exceptional)
2- As soon as the shark is caught a Bat over the head to knock out then knife all the gills on one side, tail rope over the side or head in bucket saltwater 10 mins to bleed out.
3- Remove head, fins guts, tail and put the trunk on ice few hours.
4- Fillet and skin, then fillet the fillet until bread thick. and cut into strips.
5- Soak the shark in plain milk for 4h minimum or overnight. The milk draws out the ammonia and iodine that give shark THAT SHARK SMELL and taste.
6- Rinse shark meat lightly then roll in flour or batter however you like and I assure you it is GREAT EATING.
7- Optional is to freeze before you put it in milk, then defrost... all the water that comes out after defrosting contains the ammonias and iodine as well. You could also then soak it in milk and cook, depends on how much you want to prepare before cooking.
So give shark a go, there are plenty on the coast and they have no bones and plenty of meat.