There's a trick for keeping the Erli's performance till she's nearly dry. In the picture below I marked the important buid details and you'll see why:
With the above method, you won't need to thicken your wick inside the channel. Lay the "buffer-wick" (which runs through the coil) on top of the channels openings inside the dome and try to find the optimal size for it in a way, that the lateral side of the buffer-wick also touches the inside wall of the dome (see red markings). There you have your "sealing"! OK, it doesn't seal the Erli for all times, but it gives you way much more time before too much liquid enters the dome. If you have too much of this buffer-wick you will fail because when screwing down the dome, you would cause an offset (due to friction) of the buffer-wick and that results in "opening" the juice channels again. That's the whole trick. OMG. I hope you can follow my explanation....sorry if that doesn't make sense^^ English isn't my mother language.
Cheers,
C H
EDIT: Oh, I forgot to mention, that with this setup you won't have to close the AFC while refilling! You have enough time to refill before the Erli gets flooded ;-)