Mind control a person on the other faction
Target that person
Cast A buff
In the delay, the buff will actually stick on them. I don't know about other people on your team buffing them, I've never tried it.
It seems kind of useless, but I play on a pvp server and don't want to mess with pvp some times while farming. I can do this and 9 times out of 10 the person will just grind next to me and leave me alone.
It also works for instant cast heals, such as renew.