shooting them up would be a waste - i have done it myself with liquid phenobarbital. there is no rush whatsoever (it still takes 15 minutes to reach peak levels even when injected), and the oral bioavailability is very high
personally i didn't find much use in it. zero recreational effects. i didn't test it as an anxyolitic but it could be a good one, in theory.
be careful, this shit lasts very long, like two full days or so, so don't redose. it also kicks in very slowly, over the course of hours. dosing is between 100-200mg.
above 200mg i blacked out around 15 hours after dose and could barely keep myself awake. dangerous time to be in the street - i actually lost a backpack with a killer stash of pharmaceuticals that time. i don't remember how i got home