Thanks everybody - I will give it a fair trial just in case there are any 'cides hiding in it.
I'm guessing I should use the 'nuggets' in the pile for this (??) - they haven't had time to put much of themselves into the straw - and the straw probably has lots of salt from urine in it that I'd be better off without.
Incidentally I've remembered what made me doubt the need for 'curing':
I have a vague memory of Harry Dodgson in "the Victorian Kitchen Garden" with a rough sack, a couple of cow pats and a bucket. I think the target was celery, and I think the pats were fresh...
Cheers.