Did you actually see someone using it on DC?
I just tried
# bind i "vsay_team FTHealMe" Heal Me Damn It"
# bind i "vsay_team FTHealMe"Heal Me Damn It"
# bind i vsay_team FTHealMe Heal Me Damn It
by typing it manually into the console while playing. All I get is "Heal Me"
Hm, maybe this function isb turned off.
I have such a n1ce vsay script