XSwallow plugin was installed in /usr/local/lib/netscape/plugins.

If your Netscape installation uses a different location,
then move xswallow.so from the above location to there.

You should copy the sample configuration file
/usr/local/share/examples/xswallow/xswallow.conf
to your ~/.netscape directory.

More documentation and some pages for testing your
configuration are available at

WWW: http://skynet.csn.ul.ie/~caolan/docs/XSwallow.html