Sorry, but there's nothing like that to type into LW.
Don't know if you've already tried it, but the junk filter can help. It takes a bit of time for the filter to be trained
This is a long thread but it has some useful info.
Junk Filter
If you're using the latest version of LW, or a version older than 4.13.0, you can use Aaron's hostiles list...should stop some of the crap from showing up! Read more about that here.
The TechNutopia Fullsize Hostiles List for BearShare and LimeWire