I think you linked to the Russian BO? That's a really loose one, not the 'basic' one, and is usually used for binding off lace so the edge can stretch a lot in blocking. Have you tried the standard k2, lift one over BO that doesn't have you put the sts on the left needle and ktog. That's shown on the Casting off video and may be what you need. If it comes out tight, you can use a larger needle, or just don't pull at all on the yarn when you knit the stitches or after you lift the first one over.
sue- knitting heretic