best advice is don't invite anyone over!
Seriously though, it's a good incentive to look at your set-up. If your grow room is sealed and you're exhausting properly, you should be ok. Since you can smell it throughout the house, you're missing something.
Make sure your room is completly sealed.
You may need to wash your carbon.
Where do you exhaust to? Can you exhaust outside?
Short term fixes include:
ONA gel (I think that's what
Sparda was referring to). You can put a jar of it right in front of your exhaust so that it blows through it.
Cook something greasy when someone's coming over.
You can build a deoderizer (check the DIY section) using a bucket, fan, ONA gel, and Sta-Dri.
It's tough to cover the smell though. Best to figure out why it's smelling up the house. Good luck with your harvest!