That does not work for me. When I try "stow foo/bar" I get this error:
Undefined subroutine &main::error called at /usr/bin/stow line 568, <DATA> line 18.
where line 568 of /usr/bin/stow is: error("Slashes are not permitted in package names");
What version of stow do you have? I'm using stow 2.2.0-r2 on Gentoo Linux.