How to remove icing that has welded itself to a wooden chopping board?

[MuffinMclay]

I've tried washing it in soapy water, and it won't shift. Tried scraping it off too. The stuff is welded on.
Chopping board is too big (and unsuitable) to fit in the dishwasher.

It is very unpleasant dark green icing (experiment with food colouring that went horribly wrong).

Long soak in very hot water. Scrub hard.

or if all else fails, soaking in solution of biological washing powder will get most things off
rinse very well afterwards though

I'll go and put it in the bath for a long soak and see if that works. It won't fit in the sink.

Biological wsahing powder will be a last resort - don't keep it in the house because it gives me eczema.

It should dissolve eventually. Put a wet towel over the icing to soak it through and keep scraping away the top layer as it softens.

Lemon juice might be able to remove any staining.

I'm now jealous of your chopping board - I'd love an afternoon soaking in a hot bath!

I'm jealous of the chopping board too - tempted to join it in the bath!

How I used to love a long soak in the bath with the papers and a glass of wine on a Saturday afternoon.....

After a long hot soak and a good deal of scraping with a wallpaper stripper all icing has been removed. The chopping board still has green stains in places, but I can live with that.

Thanks all

At least interesting stains show you cook. Never trust a chef with a pristine chopping board!