Can't remember exactly what it was like either.
Last time I had it was 1990's in Japan.
It did not taste very good to me and I remember Japanese friends having the same opinion.
It was sold in yogurt like cups, and probably in other forms of packaging too. It was liquidy and the general color was whitish, maybe somewhat translucent. There was something of solid matter in it though, I recall now something like harusame. The word jelly is also coming to mind, but I do not think it is sweet at all. It was not made of konnyaku. On the other hand, maybe there was konnyaku in it. It was eaten straight, not used as an ingredient in anything that I am aware.