my friend had some female plants that he cut up and stored at an offsite location after some bitch found out about them. they hadn't gone off 24/0 light yet but were six months old.

I'm suggesting that he try to make hash from the leaves but he says there won't be any trichomes. Am I right, or is he?

You could try an dmake bubble hash or something. But if they hadnt flowered yet your friend is probably rightthat there will not be any trichromes on the leaves yet if it is still vegging.

I think you can but it will be very low yield. I don't know though.

they were quite resinous and sticky though.

Then tell him to go for it.