I used the brewers pitch sold by Jas. Townsend & Son. It is my understanding that it not true brewers pitch, but it worked very well, and does not leave a turpentine taste in the water. I don't think you will like common pitch, and it may be slightly toxic from what some say. Many use beeswax rather than any kind of pitch. Some use a mix of both. There are pro's, and cons to about every way of doing it, also bear in mind that the use of leather vessels for canteens, and such was an earlier practice, fading out in the 17th c. Tin, gourds, and leather covered glass bottles are a better choice for 18th c. America.