We don't know.
The ceremony is really only ever shown in the one episode, "Allegiance: Part 1", that you mentioned. (I confirmed this by searching through scripts of all episodes with Tok'ra in them, rather than relying upon memory.)
However, all we see is that the gate has already been dialed off-screen , and the wormhole is merely activated on-screen. We don't get do see any of the runes being selected, in any order, or any chevrons being encoded. I watched and rewatched the scene, but there's clearly no additional details to be had.
My guess is that they simply dial one of their other occupied or allied planets, where they can be sure the gate will dial and not garner any unwanted attention.