Yeah, I don't know what it is, but I tend to get stuck sparges if I don't throw them in. Perhaps it's my crush, although I have my barley crusher set at 39/1000ths of an inch (I used a feeler gauge), or perhaps its because I pump wort out of the mash tun. In any case, this solved that problem. For the extra dime, why not? I suspect it also speeds the lauter up when I wouldn't otherwise get a stuck sparge.