Effects Pedal on What a Waste ?
 

I was listening to rather ripped today and i really liked that warbly/watery -like effect that happens to the song form 2:42-3:00. does anyone know what it is ?

sounds like a chorus pedal to me.

then again, it sounds as if there was something else in the mix, too.

Yeah, it was most likely a chorus pedal of some sort. Those give you a "watery" sound. I know that Kurt Cobain used an Electro Harmonix Small Clone during the Nevermind recordings and that is what gave his music that "watery" sound.

It could be a flanger with the modulation and speed set very high and the output set to feedback into the signal.