We use aspirin as mentioned in Mum's post at the top.
One reason why it 'seems' to work, is that when one uses an alternative method for battling blight - forgetting all the myths etc., one tends to check over plants more frequently, and therefore any blight present gets a look-in much earlier!
I think that there's possibly a little too much 'science' creeping in which usually obfuscates the issues rather than solves them! We all know what happens when too many 'experts' start wailing at each other, they all think they're right!