Facebook logout url not working

https://www.facebook.com/logout.php?next= "mypage" & access_token = "mytoken"

when I navigate to the URL from the browser, the browser is not redirected to my redirect URL, but

redirect to facebook.com/home (it doesn’t even log the user out).

I'm not sure what I'm doing wrong.

for the "next" parameter, which URL should I refer to? Website with Facebook or app domain?

and ... should this redirect url be encoded as www% 3Fmysite% 3Fcom ??

I tried all of these and still cannot log in. Has anyone tried logging out with a url?

Any help would be appreciated.