Just say it really fast and most of the time they will say "what". If you want to change it to "homo say huh" or if the persons name is Bob you say "Homo named Bob?" Also applies whenever the person being pranked response right after.
Me: Homo Say what!? (Homosaywhat)
Peter: What?
Me: Haha.
Peter: -.- douche.
Me: yeah I know.