Yeah either way BSSs are awkward as fuck. I prefer to do them with DBs on a bench just because if you fail you can just drop the DBs. But of course that limits you to DB weights you can grip comfortably. On the other hand, it's good for grip strengthening.
I hold the outside weight on the outside of my leg and the inner weight in between my legs. Start with the weights on the ground, then you can adjust your stance so you're in the best position before picking up the weights. It just takes a bit of adjustment but you should find a good position after a few attempts.