Geoff the Duck asked some good questions:

Do we need some form of attribution - whose local idiom?
Which Country?

Yes, that would be useful.


What the user actually intends by to comment?
Yes. For instance: In the southern USA an old expression is, "barking up the wrong tree". I think this refers to 'coon hunting and a dog that isn't indicating the tree where the raccoon is actually hiding. But in common usage it can be used to describe an erroneous or useless action by someone.

Are we looking for things such as
"About as much use as a chocolate teapot."?

Yes. But please don't limit yourself to insults such as have already been covered in other threads.

Thanks!