Thanks for the tip off Gold
Hard to find on their website but I've just ordered a tanker full - we use a lot of water.
I didn't think you could drink purified water, but you can with this resin! And it reduces/extracts the (pyrolite) content in your urine so it probably helps keep your "pipes" clean.
If it works I'm going to get it installed in the house so my wife can benefit from the "extracting" too.