Five seconds in google.
It's PG with rules against swearing and not safe for work.
Here's what you do:
Go to the off-topic place and make a topic about a subject, and just start talking about it normally. Don't bother to introduce yourselves, just give yourselfs non-troll usernames and pick an odd topic. Don't wait for other people to post, have a discussion without deliberately provoking.
Now, the trick would be to pick a discussion topic and prepare it beforehand. I can't help you there. Ideally you'd want something that could turn inflammatory, but not religion because that probably wouldn't fly.
My suggestion would be whaling, because furries are ecofags and would automatically side with Greenpeace. So, look up lots of information on Whaling beforehand and try to skew it towards whale meat being worth hunting. You could probably then turn it into a survival of the fittest or meat consumption in general debate.
But make sure to drag it out, and don't give up the game right away. Also try to avoid any troll tip-offs like proxies or whatever, even if you just claim dynamic IP or something.
Just, like, think about it and plan it out before you begin. Subtle is the key word here.
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Ah, we are high school boys,
the miserable high school boys.
If we were girls, we could get popular by doing anything:
rock band, jazz band,
karate, kendo, mahjong, cyborg, synchronized swimming...
On the other hand, high school boys are
useless outside battle and sports anime.
But they're recklessly trying to make a slice-of-life anime about us.
Ah, we are high school boys,
the miserable high school boys.