whoah, thats . .. creative?
i dunno man, cold boosts the blood flow thats a plus maybe? the absorption takes longer, better to have small cubes....it may be easier to administer, it does get a little messy with a syringe lying on your back with your ass in the air n all, this way you could do it standing up, midwalk even :O
guess a bit smaller urge to take a dump immediately after but thats about it...
I'd do it right now but i'm out of drugs :l