Grass stains on white trainers - any ideas?

Stains are gone. He said he tried Vanish and white vinegar applied with a toothbrush and that did the job. Thank you for your help.

Try glycerin. I used to use this for grass stains which were otherwise impossible to remove from white football shorts.

Nail varnish remover - acetone - dissolves grass stains.

(Who remembers mashing grass and acetone and dripping the result on to filter paper to demonstrate chromatography in 1f chemistry lessons?)

Thank you everyone. I'll pass on your helpful tips and cross my fingers. He's 32 so not going to do this for him!

Magic sponge (that white cleaning block), Barkeepers Friend or stain remover for upholstery.

Vanish

Methylated spirits.

Original Cif (Used to be Jif) and a damp cloth.

My grandson uses this. Similar stuff to what we used in the 70s for our Dunlops!

www.amazon.co.uk/SNEAKERSER-Flexible-Sneakers-Trainers-Footwear/dp/B08W581GVQ/ref=asc_df_B08W581GVQ/?hvlocphy=1007092&linkCode=df0&hvptwo&psc=1&hvnetw=g&hvadid=511147411676&hvpone&hvlocint&hvpos&hvdev=c&hvdvcmdl&hvqmt&tag=gransnetforum-21&hvtargid=pla-1223440229266&hvrand=3703616691679503802

White vinegar?