Saturday 12/9 only, Bath & Body Works [bathandbodyworks.com]
will offer two great deals - Buy one get one free Wallflower Plug units (these plug into an electrical outlet; the lowest priced itme is free) AND $2.95 Wallflower Fragrance Bulb refills (limit 15). Online, use code PERFECTDUO for the promotional prices (no other codes will stack). S&H is $5.99 for all orders of $10 or more.
In store, you can stack this offer with any promotional coupons that you might have. YMMV - stores should still accept this $10 off $30 coupon [bathandbodyworks.com]
that expired on the 7th as it's within the 3 day grace period (B&BW coupon policy - posted on their Facebook page [facebook.com]