I recently was given a 50 pound bag of onions, which I dutifully sliced up and froze. But the smell of onions persists in the kitchen. Help!
Boil a pot of vinegar and the smell should go away
I've never tried it but coffee grounds soak up alot of unwanted scents. You could put a few cups of coffee grounds around the kitchen (depending on how big it is) for a few days this might do the trick. I used to use this in my car ashtray when I smoked to get the smell out of my car, it worked like a charm.
Try lighting matches. The spark gets rid of unwnted smells. You may of course have to light a few and be sure to ventilate after doing so! And next time, you should try lighting candles around your cutting board whilst you chop away. The fire burns the acids coming from the onion. HTH