I agree with you on this;
The only way for them to reduce their ever-increasing body temperature is to make themselves comfortable, playing and rolling in mud which is speculated to provide the same physiological effect to sweating; in other words, when you see some pigs wallow in the mud, they are actually "sweating".
It is not gainsaying that pigs are dirty and disgusting , one could imagine how people love eating the meat. I recently engaged some pork eaters in a discussion and they said to me, that "pork is delicious" and all of that. But for me as a person, looking at the dirty nature of the animal, I doubt if i'm ever gonna have a taste of it.
Can't comment much on that since I have never tasted it but some of my friends do claim that porks are much delicious than any chickens or beef.