You cant 'repel' demons with earthly items. Why would a lovely and versatile flower like lavender be connected to demons in any way. The beings we call 'demons' are not effected by any earthly item. You have been watching too many movies. Garlic, wood, silver, 'holy' water, etc. None of this has an effect on demons ourside of movies, TV and books. The only thing that effects a demon is the power of God Himself.
Only Jesus s presence in people s hearts repels demons. Nothing else. Thy act as if other things repelled them, but those things dont. But Jesus s presence in a person s heart, praising Jesus in prayer or even music, reading the Bible, that repels demons. Gby.