I have used this stuff in the past in relation to gout with some success:
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It seems to act as a diuretic and helps you piss like a fiend. I was able to order it via Amazon US (not sure if the France branch carries it). It requires you to drink a lot of water in conjunction so you can flush the uric acid out of your system and not get dehydrated.
I have found that being steady about drinking a gallon of water daily, gout attacks can be avoided. If I feel a hint of ache in a foot joint, I drink about forty ounces of water right away—I have been able to avoid a full on attack close to a year by being diligent about hydration.