I think 'throwing egg' should be accepted. To me that implies several eggs.
Added. I agree that it can mean both singular and plural in Norwegian too.
In English I think using the singular implies a continuous substance, i.e. the inner white and yolk of an egg extracted from the shells.
If we're just throwing whole eggs at someone and expecting them to break on impact I would always use 'eggs'.
i agree with this. If they are in shells it should be said plural since they are contained in multiple units. If you had say, cracked several dozen eggs into a bucket and threw it at said politician, you could say "throwing egg at.."
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