What is the ruling on dogs touching clothes and the body; is it necessary to wash seven times, one of them with earth, by analogy with a dog licking a vessel, or is it sufficient to wash the place of impurity once until it is removed?

What touches the body or clothing from the impurity of a dog must be washed seven times, the first of which is with earth. Soap and similar substances suffice in place of earth, according to one opinion. As for an ordinary person, he should emulate a scholar whose knowledge and piety he trusts, and he is not obligated to follow the stricter opinion.