<human>: Can you give me the gist of the text in a nutshell?

I am a TA of a popular course and each semester a bunch of my friends or acquaintances from HS whatnot happen to take this course. 

I always get a wave of messages on FB about classwork, which I don't like. This is FB for one thing. I also don't have time to answer your questions outside class. If you need me, email me, or preferably, see me in class or during office hours.  

How should I politely tell them to fuck off? I just told answered someone's question like 5 minutes ago, which I probably shouldn't have done, since I'm just enabling their behavior. However, I went back and added that "If you have any more questions, I have office hours every Monday at 2 PM." I'm guessing this is about as direct as I can get without being rude, right?
<bot>: I'm getting messages of a professional nature on FB; how can I redirect these inquiries to a more appropriate medium/time?