There is an aggregate cap of 10(?) item drops per day in this zone. After this number of items have dropped, none of the native monsters in this zone will drop anything.
You cannot banish monsters in this area. Attempting to do so results in the message:
Nothing gets into our[sic] out of this place. Except you, apparently.
Standard effects tied to the banishing source such as insta-kills and running away still apply.
Batter Up! will not yield this message, but still cannot banish monsters.