Mine/Mikes,
ate from a clip no problem. They just kind of suck it in, I guess mimicking scraping it from rocks and glass. Dont really rip it like larger tangs do.
If the clip does not work, perhaps as bit wrapped around a pvc pipe may. Its like algae on the hard surface for them then. More natural but still kind of messy. I have also heard of using algae wafers for fish like them, if they wont take to clipped algae sheets.