Hmmm. Never tried it, why not make a small batch first.
It seems it would be better to make some sort of infusion with it, wouldn't the nori eventually go bad if left in strips? I don't know. Or you could grind it all in a coffee bean grinder. Just trying to think of how to use it, lol. When I play around for colorants, I put the herb or what have you in OO, usually in a muslin bag to not have to strain too much, and let it sit for 6 weeks, or put in a pot of water and let it gently heat for a few hours for immediate use. That avoids speckles and exfoilients.