When you mention pigs and cleanliness to me, all I can visualize is that fat pig turd on Quintus Caecilius' head.
"Don't mistake me, I really do appreciate everything you're saying, Quintus Caecilius," he said, "but the trouble is you've got a big fat pig turd on your head instead of a crown, O King of Etruria!" Out came a giggle. "Go and have a bath, then tell us again. We'll probably manage not to laugh." (Page 47 in the edition I used.)
All of our folklore equates pigs with filth. A cluttered room is called a "pigsty". An unbathed person is characterized as being a pig. In the cartoon series Peanuts, the character "Pig Pen" was always surrounded by a cloud of dirt.
However, all the literature and Sy Montgomery claim that pigs are very clean...
With that in mind, Montgomery tells of Chris rooting up the front lawn, leaving mud and destruction in his wake. James Herriot talks about how destructive large pigs are - usually inadvertantly. They crash through the walls of their enclosures and can crush their babies without noticing. Chuck Wooster (in Living With Pigs) also talks about the possibility of destruction and damage that a large pig can cause.
And every one of them says that pigs are clean... (And pretty much all the pictures of Chris in the book show him with mud and dirt and slobber...)
When *I* think of a clean animal, I think of a cat.
When you think of clean animals, what do you think of?