Trying Rooibos Tea Next

I came across a mention in a Facebook group that said rooibos tea could help against gout. I have never heard that, but since my wife drinks it practically every day, I have a ready supply.

Rooibos tea is one of the "exotic" brands of tea, made from the Rooibos bush, which grows in the area east of Cape Town in South Africa (to simplify the geography lesson). It contains no caffeine which may be a minus if you are fighting hyperuricemia to beat gout, but it contains more polyphenols (another useful chemical) than red wine. The taste is not too different from black tea, with a slight twist towards orange and pomerance. I could easily drink as much as my wife and more, and tea is an excellent way to stay hydrated. If you skip any added sugar, including honey.

I would not be trying a supplement unless there was some evidence that it works against gout, either by lowering uric acid production (like allopurinol), by reducing the uric acid that is already produced in your blood; or by improving the execretion of uric acid. All three are ways to decrease the amount of uric acid in your body (even though there is very little to start with). If you have too much uric acid for too long time, your body will not know what to do with it and stores the uric acid as crystals in your ligaments; the storage can grow into tophi (bulges on your limbs) which contain uric acid crystals and can harden over time.

So how is rooibos tea supposed to reduce uric acid, and is there any evidence for it? Googling "rooibos uric acid" gives you a huge heap pf tea merchants and health advice pages who claim there is evidence for some effect, but as usual they do not quote any studies or provide links to the supposedly existing scientific evidence.
Why is this important? Why is it not enough that "some people" say it was good for them?
Apart from "some people" claiming that dangerous actions like injecting bleach can have positive health effects, there is no attempt at objective measurement. And that is important - otherwise there is no way to compare the results.

So is there anyone without a vested interest in rooibos tea sales who says that it could reduce uric acid? Actually, yes. There was a study done at the university of Nagoya, in Japan, which seemed to point at some effect when rooibos tea was injected into the liver of experimental mice (you can buy a kind of mice which are mutated to become hyperuricemic - otherwise animals reduce the uric acid and do not have the same problems as humans).
Apart from the impracticality of injecting tea into your liver, increasing the amount of polyphenols in my body should enable them to oxidize the uric acid and tender it harmless.

But there is a problem with that theory: While polyphenols are very useful, they are not taken up bery well by your body. Only 5% of all the polyphenols in tea (and anything else) are taken up by the body (through the lower intestine). So unless you inject them into your liver directly, they have very limited effect on your uric acid level.