For druids I thought of a way that I was not sure works until I tried it but you can have 1 hour of thorns by following the steps (being a druid I hatted using the thorns buff so often) well for duel spec there is
>Have thorns glyph on OS
>Buff with thorns
>Swap to MS keep the buff for 1 hour
Or
>Buy the thorns glyph
>Buy one of the current minor gylphs
>Put thorns on And Buff
>Replace with minor gylph of choice
>Thorns for 1 hour
You will keep thorns and if you try to rebuff yourself with thorns you won't be able to due to the fact about the timer.
I am not sure if this is a repost I looked and found nothing however if this happens to be a repost please link thread too! Enjoy leveling.