The art of a good freeze out, at work?????

There is this girl I work with and I think it’s about time I froze her out – due to the way things are going. I’ve heard freeze outs work really well as a way of overcoming LMR or when in a club talking to a set, but I’m wondering if it can also be effective in a longer time frame environment, like a girl you work with etc.

From what I’ve read it seems the key is to just CASUALLY ignore her, or respond/talk to her in a casual indifferent way. In other words, do not make it obvious your upset with them. Are casualness and indifference the key to a good Freeze Out?

So, regarding my situation I was wondering:

How long should a freeze out occur for?

When to end the freeze out? As soon as she starts talking/chasing you again or wait a bit longer after that?

Also, if this girl starts talking to me in the office (as she often does, while walking past each other etc), to ignore her would make it too obvious. What to do? Just casually cut the conversation short making out I’m busy etc?