why would you bother with a snap cap in a TT? you couldn't hurt them if you started dry firing now and continued into old age?
I have seen it written that people have blamed a broken firing pin retaining pin on dry firing. That may not be true, but I can see how having the firing pin bounce off the retaining pin, rather than being cushioned by a primer, MIGHT eventually lead to something.
That should work.I have an old Azoom cap in 9mm that fits and functions in both of my TTs