I have heard of using milk, juice or beer instead of using distilled water in a cold process soap recipe. But I found this recipe from the Soap Queen that still uses distilled water but has avocado puree in it.  I have never heard of adding fresh fruit or vegetable purees to cold process soap before but according to the Soap Queen it has long been a staple in the soapmaking community.  She said purees can add color and skin-loving properties to the bar and it can give the soap a luxurious feelings.  Unlike some additives, avocado does not contain a large amount of sugar.  If you add sugar, which can be found in fruit, can cause excessive heat to a cold process soap batter and make it difficult to work with.  Are you interested in learning how to use avocado in a cold process soap?  Check out this intermediate project called Avocado + Spearmint Cold Process Soap Tutorial.  This project makes about three pounds of soap and takes 1-2 hour to make.