Is it sufficient to rub a shoe on wet ground to remove impurity, just as it is sufficient to rub it on dry ground?

Purifying the bottom of a shoe by rubbing it on the ground is an opinion within the Hanbali school of thought, but it goes against the relied-upon view. The relied-upon view is that it is not purified except by washing, and this is the opinion of the majority of scholars. Those who hold the view of purification by rubbing have differed on whether it includes dry and wet impurities, and whether it is an actual purification or an exemption. It is stipulated that whatever is rubbed with must be dry and not wet. In conclusion, the purification of the bottom of a slipper or shoe by rubbing is contrary to the opinion of the majority of scholars, and whatever is rubbed with must be dry.