Hxrmøny uses the Double Accept method. She says that she is going to give away a RIM Headdress at her den. When she's gathered enough people, she announces that basically the best trade for her storebought item gets the Headdress.
She says you need to accept twice then decline, which isn't a real thing because you can only accept once then decline. Regardless if people start saying that she's scamming or if she gets the item she wants, she locks the den and logs out.