I had seen that...I opted for this instead which she does drink so long as she takes that first lick...the first lick is the hardest!
It actually looks tasty...your boy might like it too.

https://www.amazon.co.uk/dp/B0F79XD5NJ?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Think I will order a bottle of that RECOACTIV, though, can't do any harm and as she does drink the Hydra Care stuff, she might deign to try the RECOACTIV.
Thanks for the suggestion.
Been trying her on a few different Phosphate binders too...little success there, either.

The garden birds are having a right old feast at the moment with the amount of cat food being turned down and put out for them!