The simple solution to the problem is to disable the meriting of WO posts. Much like how signatures were disabled in that thread, it will discourage spammers from flooding the thread.
What would also discourage that kind of behaviour is people not meriting those kind of posts as its not that hard at all to differentiate a legit one from merit fishing if you spend some time there (or at any other board/topic).
My question is, why regulars there are not more selective when meriting?