I've been under the impression that Tazorac is very effective, but that yes, it costs an arm and a leg and is therefore packaged in pretty small tubes.
So, for an adult, it would be best suited to hands, face, maybe some of your arms...but not really a practical solution for your entire body.
Did I get this wrong?
I'm really happy for everyone that's tried it so far and is having success. Few things in the world are better than having ichthyosis and finding something that really improves it.