No Japanese market in the vicinity has heard of Tengusa, so I tried Kombu. Kombu allowed me to skip the tedious steps of making a gel sheet out of the tengusa, dehydrate and then roll it up.
So do I announce my failures to the world? That eating kombu was like eating a rolled up piece of kelp you step over at the beach? I ate one and spared my husband. Sea vegetables make good compost.