I used to use both, but haven't for a while because I'm not sure it really matters for me since I lift and dump my wort into the carboy instead of draining from a valve. And also, I agitate my chiller when it gets to about 70-80F to mix the wort more and chill faster. So I'm not sure it even helps to use the stuff for me. But maaaaaybe it does...hmmm.