Second to Deeli's comment on a big NO on reusing cracked (or uncracked) trays that previously held fish, meat or poultry; if they're cracked, irregardless of what may have been on them I wouldn't reuse them.
No matter how well you think they've been cleaned, my guess is that bacteria may still lurk in the crevices--I'd toss 'em.
By
05/10/2010
Could you explain in more detail what you mean?
And if you're talking about reusing trays that meat, poultry or fish comes in the answer is 'absolutely no' if even there are no cracks!