Schulsk is the word you say when you want to say the word sculsk. It means nothing except "schulsk" whatsoever.
"Why would I want to say that?!" you may ask yourself now, but if you would just shut up, it would be explained to you shortly. If you, for example, just suddenly get an unexplainable urge to say something, anything at all in fact, why not "Schulsk..."?
Example: You're with some people, and nobody has said anything at all for quite a while. Then you feel the earlier explained "unexplainable urge to say something" crawling up your back to spit you in your ear:
Everybody else than you: WT...?!
Then they all start talking, laughing at you and living happily ever after.