Water bottles work well with many Basenjis. The breeder I got Perry from used a spray bottle, but I got myself a nice little squirt gun for more accuracy. I don't need it often, but it is effective. It is amazing how well he can control his urges if I simply pick it up. However, I doubt it would break up a full blown fight, so if you think sh*t is about to happen I would get ahead of it before they are too far gone to care. If you are lucky they will just decide to play. And Anubis should prove a good influence on your new girl.
Any chance the previous owner wanted rid of her because she had difficulties managing her? Some people don't understand Basenjis and run into problems as they start to mature. If this girl got snarky when disciplined and they didn't handle it right, they could have created a problem.
Oh, and I'm sure you will want to get her DNA'd for Fanconi, since you don't know her background.