f5 sharepoint tenacious session issue

Not sure if this is too late, or helps at all, but I have had some success in a lab environment. Just attach a default stream profile and this irule.

This will inject some javascript into the bottom of the page the looks for a user to close the browser, then transparent redirect to SignOut.aspx, which APM interprets as a logout and terminates the session (and persistent cookies). May not work in all environments, and this code only supports IE. For Firefox and Chrome you have to return a message. http://stackoverflow.com/questions/9626059/window-onbeforeunload-in-chrome-what-is-the-most-recent-fix

when HTTP_REQUEST {

    Looks for SharePoint hangup, kills APM session.
    Could also set via Logout URI Include setting in APM.
    if { [string tolower [HTTP::uri]] contains "signout.aspx"} {
        ACCESS::session remove
    }
    STREAM::disable
    HTTP::header remove "Accept-Encoding"
} 
when HTTP_RESPONSE {
     Check if response type is text
    if { [HTTP::header value Content-Type] contains "text" } {

         Define the stream replacement
         Change the 15 in the following line to the version of sharepoint being used 13 = 2007 / 14 = 2010 / 15 = 2013
        STREAM::expression {@@ @}
        STREAM::enable
    }
}