Alternatively, if all you want is to keep it from appearing on your own screen, you can "edit" the text that you see. It won't affect what others see, of course.
on ^*:text:*:#: {
echo -a < $+ $nick $+ > $replace($1-,someword,something else of blank)
haltdef
}
Granted, this is just a basic example of an echo. You may want to include timestamps, colors, nick modes, etc. so that it looks like your normal chat lines.