Just whisper them back something like...
"I will buff you when you tell me what *you* think the most annoying thing for a cleric is"
or
"ill buff u, but first, please define KS"
or
"sure, but first tell me how u would like to be asked for a buff please"
or
"stop bugging me or i will tell everyone in ClericChat not to buff <their name>"
meh...or just buff them and they go away...or buff them with the poison buff and see how long it takes for them to figure it out
