Water

I was wondering what was used for thousands of years before soap was invented, so I did an electronic search in the Bible for the word "wash".  The phrase "wash with water" came up  repetitively.  It is the mechanics of running water that washes away germs.  Water is a file solvent for salt.  

pH of Water
 
To learn why pH is important, please visit The Acid Mantle Web Page.  In a nutshell, we want products with 4.5 to 6.5 on the skin.  It's important, because alkaline water and products cause drying of the skin. 

Water piped in from water companies can be alkaline to preserve plumbing and to prevent lead and copper from seeping out of pipes (acidic water corrodes plumbing).  The water being piped into my home comes in at a pH of 9.  If your water is highly alkaline, adding a splash of apple cider vinegar--which is acidic--to the bath can help combat the problem of dry skin (restoring acidity).  I use a skin toner to restore the proper pH on my face.

Well water tends to be acidic.   If it's too acidic, adding some baking soda will raise the pH.

Distilled water has a pH of between 5.6 and 7.  
 

Testing pH

If you experiment with the pH of your water, get a pH test kit.   They are not expensive, and you can get them from your local pool store.  Also, pool stores will test your water for you.  I don't think they'll charge you.   Further, you can ask your water companies to come and test the pH level of the water in your homes.  
 

Jacuzzi to Lower pH

If you have a jacuzzi, turning it on and bubbling air through the water will lower the pH of the water so that it is close to 7 (neutral) by dissolving some extra carbon dioxide in it.  (Thank you Physics Professor, Dr. Bloomfield.)  
 

Epsom Salt (Magnesium Sulfate)

Epsom salt is hydrated magnesium sulfate (about 10 percent magnesium and 13 percent sulfur).  It will lower the pH of the water in the bath and is especially useful in treating wounds and widespread eruptions of the skin, removing crusts, scales and relieving inflammation and itching; and it can help take the sting out of insect bites. It didn't sting or burn my skin like salty ocean water did when the skin was raw.  (2 cups of epsom salt in a warm bath.)

Epsom salt is also used to make wet dressings.  It helps drain swollen tissues, boils, infection and will draw toxins and splinters out of the skin.  (2 cups of epsom salt in 2 cups of hot water to make a compress; apply as a wet dressing with a towel.)  
 

Bath Water

See, also, The Bath Web Page to learn why people with dry skin and eczema might consider cutting down on the number of baths and just showering briefly instead.