Substitute: Most drug and supermarket chains and even Walmart have Kodak BW400CN.
Agree it's better than no substitute, but unless you have the capacity to print color, my understanding is that it's not a good choice. The BW400CN is designed to print on RA-4 paper AFAIK.
The Ilford B&W C-41 film has a clear base like B&W film, but supposedly the Kodak film has the orange mask. That may be wrong, but if it does have the mask then printing them yourself on regular B&W paper is a problem.
Still better than nothing, but hardly the same. I'd find a CVS if I could. I'd get the BW400CN if I couldn't.
MB