Remove rust from on sandstone paving - Caused by lawn fertiliser (incl. photos)

[scotpot]

Stupidly, I didn't realise that lawn fertiliser could stain paving, so despite brushing the paving after using fertiliser on the adjacent lawn it's still quite stained.

The paving is an ivory sandstone and the supplier has recommended their own product; Pavtuf Rust Remover (which I note is non-acidic) but it's terribly expensive at £33 per litre.

I will (resentfully) pay this if it does the job far better than other products.

Question: Does anyone have any experience with this? Alternatives?? (Lithofin Bero or Lithofin Rust-ex)

[RAPressureWashing]

The Pavetuf rust remover should get most of it off, I have tested it and it isn't to bad, we usually use a different product ( a Limestone restorer) with a floor buffing machine and honing powder.