Completely removing directories -- how?

[Michael Gersten]

How can I completely remove a directory from CVS?

Some build directories got checked into a project by mistake. This
directory contains only .o files.

cvs rm -f will remove it, but later uses of 'cvs update -dP' will fail
(because it is still tracked as an empty directory, but isn't anymore.)

(aside: I know I can physically delete them from the repository -- I'm
looking for a CVS command, that is essentially an 'uncommit')

Michael