If Muslims eat pig meat without intending to, there is no sin on them. The correct view is that pig-related impurity should be washed only once.

If you touch a dog when it is not wet, then your hand does not become impure. If you touch a dog when it is wet, this means that the hand becomes impure and must be washed seven times, one of which should be with earth.

Dry impurity does not pass to the one who touches it, so his garments do not become impure and neither does his body. If a person sits on dried urine, his clothes do not become impure as a result of that, and he does not have to wash them.