It's a shame about Dr. Lee getting shut down by the Feds. I used some of his stuff and was pleased with it, I haven't used the Xandrox 15 though. I do use MOPC labs 15% with 5% AA and have been very happy with it.
I have only used the 15% with 5% AA, it doesn't have much ppg in it but the Azelaic Acid stays sticky on the scalp for at least an hour, as with most minoxidil it absorbs better on a hydrated scalp. Here's one on ebay that doesn't have the AA in it but I don't know the drying time as I haven't tried it yet. http://cgi.ebay.com/15-MINOXIDIL-for-ha ... dZViewItem