Attaching cement board to terra cotta block

[qitofixit]

The previous owner in my 100 year old house had installed a corner bathtub with a personal shower attachment. The walls abutting the tub were tiled with the tiles on the original wall being set directly on the old plaster. Recently some of the grout failed and water got into the wall. I want to remove all the tile and install the waterproof Duma wall panels. The only problem is that my house is framed using terra cotta blocks on all the outside walls. Once I remove all the tiles, top coat plaster and crumbling sand based plaster (mortar?) what do I attach the wall panels to? My first thought was to put up cement board and membrane but what would be the best way of securing it to the terra cotta? Thin set? Gorilla glue?
Help, I need my shower back!

 

[AC Power]

I would use a Lepage product called "PL400". This glue dries in about 48 hours, provided it's warm (+70deg F). This is called a sub-floor adhesive, but it has been used for many purposes. I have owned my home for 30 years, and PL400 has been around for approx for quite some time now.

I am not a salesman of this product.

Check out:

https://www.whatsinproducts.com/types/type_detail/1/15511/standard/p%3ELoctite%20PL%20400%20Subfloor%20Construction%20Adhesive-11/14/2014/p%3E/13-010-082