Here's a google photos link:
https://photos.app.goo.gl/ykSo3tN2JLxrXrEW7
It mostly cleans the sand bed and only cleans the rocks as high as it can prop itself and reach with it's trunk, just like in the video. I'm still working on a solution for the GHA on the upper rocks, but the lower rocks are super clean. Bought a pencil urchin, but it isn't interested in GHA. Grows too fast for the trochus/astraea snails. Looking into a turbo and/or tuxedo urchin.
But that conch works wonders on my zoas and mushrooms when the GHA gets on them. I just take them off the rocks and leave them on the sand bed for a couple of days.
I've also used hydrogen peroxide on zoas, and it works, but they are unhappy for a few days. I've never had one melt, though. Just dab it with a saturated Q-tip until it bubbles a lot, best if the zoas are already closed up.
For GHA on your rocks, in absence of an effective CUC, I'll copy to you what I just wrote to someone else:
I've been using a feeding pipette and a baby bottle nipple cut with an opening at the tip just large enough to push the pipette through and using this in the tank to dispense hydrogen peroxide onto the GHA in patches. If you keep the air in the nipple, press it on top of the GHA and then slowly drip the peroxide onto the GHA, you basically get a full blast of peroxide on the GHA that you can let sit for a few minutes. Afterwards, the patch goes white in a day and completely clears in a few days. Do this every day or two and you'll slowly clear off all the rocks--I don't do more than one or two patches a day so as not to put too much h2o2 in the tank.
Hope that helps!