Cob foundation cement

[vtrac at alternatives.com]

Hello everyone,

We are building a small cob meditation space in our backyard and are now in
the process of building our stone foundation. We already have the rubble
trench in and are now laying the large stones. Our wall is only about 12
inches wide which makes it a little harder to dry stack.  We are
considering using some type of mortar to jam into the stones but do not
want to use cement. We are thinking that perhaps straight cob would work
fine, but we are wondering what natural materials could be added to give
the cob more strength, adhesion and waterproofing properties?  Has anyone
drystacked a narrow wall (1 stone width in size)? How solid, safe is it?
If anyone has any experience with this thanks

Ian Marcuse