Jogeephus, I agree that killing the pig first would be the humane way but the some indigeneous Solomon Islanders are lazy, so having hog tied the poor beast, throwing it into the fire is the easy way out. Life in the rural Solomon Islands is still very primitive and hasn't changed much in millennia. I use hot water myself, like you. It doesn't take long. I don't immerse the carcass, just cover it with hessian sacks and pour the hot water over it in workable areas. No need to rush. We use deg C here now not deg F. Your 140 deg F subtract 32 then multiply by 5 & divide by 9 = 60 dec C. Exactly the temperature I aim for.
All the best, Vernon