السَّلَامُ عَلَيْكُمْ وَرَحْمَةُ اللهِ وَبَرَكَاتُهُ AhsanaAllahu ilaykoum Is also the impurity of dog removed by anything if the place becomes pure or will it remain impure until washing 7 times with dirt?

No, the dog is the exception. Any other impurity is finished once the place is washed and clean, but this one is seven washings with one of them using soil, or soap in place of it, and dry contact with a dog transfers nothing at all.