What do you exactly mean in "never works"?
I traded flights many times without problems. The only times it wouldn't work were when I hit "rules violations".
Is it never working with you and/or with all the colleagues you know as well?
If you get swap requests, means it worked in a way...
To get rid of it (why???!!!!) : go to "Trip trade" -> "Personal settings" -> tick "I do not want to be bothered by other crew about a possible trade, unless I have asked for a specific trade myself and there is a possible trade match" ... not very fair though
(and I don't know that much, it's better that way
)