Ok, there appears to be an epidemic of un-ladylike behavior in bathrooms. Maura gives some backstory:
this note appeared in the staff bathroom one afternoon. rumor has it, people were not flushing enough and someone got really upset. in fact she dictated the sign to my friend verbatim (with the quotes) before posting it!
I'm not going to discuss what "remnants" could be. I guess it's marking a euphemism, which is acceptable.