I have a pretty indiscreet wax pen so I can smoke in my room but it does smell a bit, I currently use incense which works just fine, but I really wanted to ditch the incense for an oil diffuser, just don't know if the oil would be strong enough.
No I don't think so. Weed smell is very strong and distinct. Just covering it up won't keep it out. The smell gets into fabrics. Not sure if this helps