If you mean by this going around and randomly ask people for free....I wouldn't. But just saying trick or treat is fine. For example, I have a room that has candy machines in it from last year and some people have come in saying "Trick or Treat! Can I have some candy?" And I tell them "Sure, there are candy machines all over the room!" And they are happy to just get an answer and come in the room and chat and eat candy. It's a fun way to meet new people. My room has been full pretty much every night.
The hosts will have special games set up all month where you can win halloween themed items or pins. They have already been giving out bat bags this week in host events. Check out the calendar and try to make a few of them. But it won't be like last month with hosts just giving out stuff. Host Lily was in my room the other night and everyone expected to get something from her but she told them that dreams month is over and the hosts will not be giving out stuff except in their games or events. Hope that helps!