To make wudhu or ghusl with the water of those places where some nation was punished by Allah Ta’ala, such as the people of Thamud and Aad, is not proper. There is also difference of opinion in this matter. It is therefore better to abstain from this. But if one is compelled, then the same rule as that for zam zam water will apply.
An oven which has become impure can be purified by lighting a fire in it on condition that after it gets hot, no traces of the impurity remain.
If an impure piece of ground is covered with sand and the impurity gets concealed in such a way that even its smell does not come, then the surface of the sand will be pure.
Soap made with impure oil or fat will become pure.
If the place of venesection (cutting of veins) or any other wound from which blood or pus came out became impure and washing it will be harmful, then it will be sufficient to wipe it with a wet cloth. It will not be necessary to wash the place after it has healed.
If an impure dye falls on the body or clothes or the hair gets coloured with this dye, it will be sufficient to wash them until clear water begins to flow even if the colour is not removed.
If a tooth which broke off is refitted with some pure or impure substance; or a broken bone is replaced by an impure bone; or a wound is filled with some impure substance; and all these get healed; then they (i.e. the impure substances) should not be removed. They will automatically become pure.