BOAB is a really great tool. I remember when they first came out, made everything easier.
You have to have it just on your hip, so that as your body bends or twists, it stays upright-swivelling in the little pivot.
The squeegee only fits in one way. The handle angled away from you. If you try to put it in the other way, you'll find it jumps out every time you take your mop out. (The mop handle catches the squeegee handle)
This means an awkward wrist-twist to take it out, but you get used to it very quickly. Persevere with it. It means not balancing your mop on the top windowsill, only for it to fall into the garden and get mucky. Also, you can do a whole house without going back to the bucket.
Philip