homemade play dough calls for alum

Shaving alum is a powdered form of alum used as an astringent to prevent bleeding from small shaving cuts. The styptic pencils sold for this purpose contain aluminium sulfate or potassium aluminium sulfate. Similar products are also used on animals to prevent bleeding after nail-clipping. Alum in block form (usually potassium alum) is used as an aftershave, rubbed over the wet freshly shaved face. Crystal deodorant: Alum was used in the past as a natural underarm deodorant in Europe, Mexico, Thailand, and the Far East and in the Philippines where it is called Tawas. It is now commercially sold for this purpose in many countries, often in a plastic case that protects the crystal and makes it resemble other non-liquid deodorants. Typically potassium alum is used. Alum powder, found amongst spices at most grocery stores, is used in pickling recipes as a preservative, to maintain crispness, and as an ingredient in some play dough recipes. It is also commonly cited as a home remedy or pain relief for canker sores. Water treatment: Alum (aluminium sulfate) is used in water treatment. The addition of alum to raw water causes small particles and colloids to stick together and form heavier particles (floc) which will settle in water. This process is called coagulation or flocculation. Fire retardant: By soaking and then drying cloth and paper materials they can be made fireproof. Wax: Alum is used in the Middle East as a component in wax, compounded with other ingredients to create a hair-removal substance. Foamite: Alum is used to make foamite which is used in many fire extinguishers for chemical and oil fires. Adjuvant:Alum is used regularly as an adjuvant (enhances immune response to a given immunogen when given with it) in human immunizations. source = Wikipedia

My mom used to put alum on our canker sores in our mouths. It tasted awful but it seemed to help heal the canker sores.

Alum is used as a mordant to treat fibers before dying. The alum helps set the dye and make it more colorfast.