I got Thai weed one time, it was in 1988 and it the stuff came wrapped in foil. It was really sticky stuff and somewhat dark brown as well. Super potent and super tasty, I impressed the hell out of my circle when I came up with that herb. I mentioned it being brown particularly because if you're feeding your dad some green weed with sparkly white trichomes, that might be why he thinks the effect is off. He might be looking more for the effects of something thats been aged a little bit more.
\If older weed doesn't work, maybe try feeding him some mushrooms.
Aged Thai might just be the ticket!
I hadn't thought of that.
Same for Drawoh's Choc Thai via Hazeman.
I believe these were what the Choc Thai x Vitality may have come from but I don't recall exactly.