Sounds to me like if you slip 2 as if to k2tog, that will TWIST those two sts around each other....if you slip 2 sts one at a time, it will only twist the individual sts.
SO, stick your right needle into 2 sts like you were going to knit them together (in other words, from the left side), but DONT. Just slip them to the right needle.
Then, knit one st regularly
Then, pull the 2 slipped sts OVER the regularly-knitted one.
I think the addition of "drop from the needle" is a little redundant, as one does this ANYWAY when passing sts over, dont they? What else would one DO with a passed-over st?