A number of years ago while in Hawaii I wanted to try some local smoke and after finding some that looked like it was the killer. The kid says something along the lines like "we need to hurry up"..... But I opened the baggy anyway and it had a smelled like moldy sea salt.... well that was all I needed to pass on the situation.
So later I inquired from some locals that I had met and it turns out that alot of guys were selling some kind of fake weed and normally its sold in a vacuum sealed type little bag so you cant smell it. One guy even had a little roach of some real stuff to sample or they would have a real bud in a little ziplock type bag to look at but it was not for sale....only the bunk fake crap in the sealed bags.......so I too can understand why someone would ask the question because I have seen it for myself and it looks real.
My guess is the stuff I saw was some type of sea weed but it looked real as it was green with red hairs and crystals.......