There is a wide view of what to mix and not mix on epoxy glue. However when I do this to brush on a firewall I typically mix the two glue parts well, and then add in the alcohol. I add VERY little alcohol, and it is not quick to mix in.. you have to really stir it good.. it does seem to fight mixing at first like oil and water. I have never done this in a big batch so I don't know what your work time will be. If the mix is too thin I am not even sure how strong the cloth would be afterwards?
Anyhow many know more about this than me, hopefully someone will give you a better answer.