While I'm a big fan of the StackExchange site myself it doesn't really seem fair to this forum to ask for help here and then tell people to answer it on another site.
Under what definition of "fair"?
This site is providing a service to you, for free. You can come here, ask questions, discuss, get answers. You can see what others have discussed and what answers others have given. If there were only questions here but no answers it wouldn't be very useful.
A lot of forums won't allow you to advertise competing sites at all. This forum is very liberal in that sense, but you're taking it one step further. You are asking people of this forum
to help you here
but then you won't let it benefit this forum.
The reasonable thing to do would be to ask the question here and if you get a good answer, ask that person if you can also use the answer at the StackExchange site. If you go to a friend's house and he shows you something great in a book of his you don't tear the page out and take it home. You might ask him if he'll let you make a copy of the page. It's just common courtesy.