So in one of the activities (greased pig) you try to hold tight but the darn thing squooshes out of your grip, and in the other activity (tug-of-war) you try to hold tight but get a rope burn when the dry grip slips. I think I would still opt for the tug-of-war, since I’ve never forgotten the following lines from Ted Hughes’ “View of a Pig”:

Once I ran at a fair in the noise
To catch a greased piglet
That was faster and nimbler than a cat,
Its squeal was the rending of metal.

Pigs must have hot blood, they feel like ovens.
Their bite is worse than a horse’s—
They chop a half-moon clean out.
They eat cinders, dead cats.