Removing a visitor from an experiment

[#1]

We are interested in the impact of variations to our home page on users who don't redeem a coupon code on our site. We don't know whether they will redeem a coupon code when they load the home page, so we can't exclude them at that point.

Is there an API call that would let us remove the visitor's data from the experiment when they redeem a coupon? Or somehow segment them out during results reporting?

[#2]

You can remove a visitor using the Optimizely JS API. Here's the documentation source for removing visitors: http://developers.optimizely.com/javascript/reference/#audiences

[#3]

Thanks. The API documentation says "If the audience has segmentation enabled, this will not impact any past conversions, and visitors you remove will still count towards the audience's unique visitor count if their visit was already logged." In other words, this won't help - is that right? Any other suggestions?