In case anyone is wondering, there's a much more sane and graceful way to do this. The last previous answer hopes to do the same thing, but that search fails since architectures are not actually part of package names, except in special cases.
as root (or with sudo) run:
aptitude remove ~i~ri386If you don't use aptitude over apt-get already, do. It's really excellent. You can find a list of aptitude's search terms here.