Enoon, just either filter out all the black pepper from your IPA or decant the IPA off, either way try and have the least amount of particulate matter in your now black-ish IPA that you can. Then in the same jar your IPA is in, add water like ROM said until it clouds up, and then until no more clouds form. Let it sit for a few day then run through a coffee filter and voila!

I used 91% IPA, and ended up with a very pure yield.

Thanks for the suggestions house!