My girlfriend told me about this because she gets blood clots from hormonal birth control and we wish this was an option today. You should complete this survey like I did if you are interested: http://www.surveymonkey.com/s/TSKSKGM
(There are only two real risks/side effects: Heavier bleeding, and it's important not to get Pelvic Inflammatory Disease (which is another way of saying, it's even more important than normal not to get STDs. If she can handle the first, and is in a monogamous relationship - or at least, always uses condoms with people who aren't guaranteed STD free - then neither issue is severe.)
Mind you, vasalgel sounds even better to me. :)