In case you want to delete a conversation, you can use the deleteConversation() method. This method takes two parameters. The unique id (UID/GUID) of the conversation to be deleted & the type (user/group) of conversation to be deleted. 
CometChat.deleteConversation(conversationWith: "cometchat-uid-1", conversationType: .user, onSuccess: { message in
  print("Conversation deleted",message)
}, onError: {error in
	print("delete Convearstion failed with error: \(error?.errorDescription)")
})
This method deletes the conversation only for the logged-in user. To delete a conversation for all the users of the conversation, please refer to our REST API documentation here. The deleteConversation() method takes the following parameters:
ParameterDescriptionRequired
conversationWithUID of the user or GUID of the group whose conversation you want to delete.YES
conversationTypeThe type of conversation you want to delete . It can be either user or group.YES