I was talking about reverse BAir, in which you hit the opponent with the area around Ike's face; it works pretty well against people who DI away on
QD attack and
NAir at mid %s. You can do something similar out of UThrow at low %s, although I think it might be more profitable to use UAir instead. As for FThrow -> QD -> RAR BAir, it works best on floatier characters at mid to high %s but it shouldn't work if they DI properly. You can try mixing up the opponent's DI by using BThrow and DThrow, but in general, it's hard to trick the opponent if they always DI the FThrow away and down because all of Ike's other throws are relatively easy to react to.
I'll post a video about it sometime this week, but it's (very) vaguely similar to how Falco drops down below the stage when edgehopping lasers; you want to let go of the edge and drop low enough such that when you jump and QD, you'll start out in the air but then land on the stage while moving forward, thus opening up grounded QD options. I have yet to actually try it out on an actual opponent, but it seems like it'd be good as a mix-up once in a while since you can either QD attack (which forces the opponent to shield or stand away from the edge) or wavedash onto the very edge of the stage after you land.