You may purchase pure Lavender essential oil, drip 3-4 drops onto your pillowcase. I would not recommend you to use the oil burner that you need to use tealight candle for the aroma.
1)tea light candle is with flame, it needs oxygen for combustion
2)the vapour will be too heavy to bring the aroma around the room thus not achieving satisfying results
anyway am a qualified Aromatherapist. Am more than willing to help you, if you need more information, feel free to drop me an email
[email protected]
Cheers!!