The kid's been a little sniffly in the wake of her cold (Did I say sniffly? I meant she couldn't have more snot on her face if she lived in a rusted out trailer park). A few nights, it was so hard for her to breathe, she'd wake up every couple of hours as she'd come out of REM sleep.
Then I got the Vick's Vaporizer, which quietly fills her room with gentle steam, enough to keep the mucous viscous and stop it from stopping up her nose. She slept straight through the night and now confines her snot-bubble blowing to waking hours.
Best part: it's only ten bucks. There are larger, more expensive models, and even though this one's "triple-insulated" and doesn't let you near the boiling element, the paranoid among you can try a regular humidifier. We haven't tried it yet, but the user manual says you can add some kind of Vick's-brand aromatherapy.
Buy the suspiciously similar-looking Evenflo Vaporizer for $12.99 at Amazon, or just go to the drugstore and buy one ten minutes before you need it.