In relation to your reply about home breathalysers, your readers should be aware that such kits are prone to false negatives (and false positives for that matter). Irrespective of what concoctions you take in an effort to counteract the after effects of alcohol, the liver still takes 1 hour to dissipate 1 unit of alcohol (1/2 pint, glass of wine, tot of rum etc.). There is no such thing as 'hair of the dog' and copious amounts of black coffee or antioxidants will not affect this process. The only ways to ensure not being over the prescribed limit is either not to drink/drive at all or to undergo a blood/urine laboratory test.