Not quite sure what you're after, but most distro's have
core-dumps disabled via ulimit these days. If yours hasn't,
or if you re-enabled them and are running out of disk space....
Code:
find / -ctime +7 -type f -name core -exec rm {} \;
for example will delete all cores older than a week from
your box if run as root.
Cheers,
Tink