The Beholder cookies were mentioned in reference to Crucible, not Xorian. (to jump over the maze and get the horn, then jump back) The wheels in Crucible can be done by setting them to a combo and pulling the lever until it comes up.(or setting 1 or 2 wheels and jumping to the rest when the right combo comes up.)
Someone else posted a link to a video of someone opening the barriers in Xorian solo.