Lavender & Laundry/Washing
Go way back, since ancient Roman times. Indeed for most Latin, Germanic based and other languages the stem "Lav..." most always relates to cleaning or washing (lavatory, lavanderie, lavanderia, lavage, etc...).
The essential oils from most types of lavender have powerful antiseptic properties and were used in many cultures (such as the French) as such long before modern chemicals came along. French hospitals for instance would burn lavender to "kill" germs in the air and one supposes to help deal with the whiff about the place. Lavender essential oils will also heal skin burns as well.
Were the stuff grows naturally (UK, France, etc...) wet laundry would be placed over lavender bushes to dry. This would infuse them with a wonderful scent.
Being as all this may many persons cannot abide the scent of lavender. To some it smells of "old ladies", others it brings on migraines/headaches and even convulsions.
By and large what most laundry and other laundry products hawk as "lavender" scent is far from it and rather putrid to one's nose. Much of this has to do with the cost. Pure essential and or fragrance lavender oils from the best plants in UK or France is very dear cost wise. Not something you'd plop into a $2 bottle of FS.