Deleting i386 packages

[Joe Pfeiffer]

For historical reasons, my x86-64 architecture computers have a large
number of i386 packages on them that I'd just as soon be rid of.  is
there a good way to simply tell a package manager that I want everything
involving that architecture deleted?  The best answer I've found on my
own has been to use dpkg and grep to find everything with :i386, and
then construct a huge dpkg --purge command to get rid of them all.
Hoping for something a little simpler...