In reply to Wiley Coyote2:
I think the point of oven-ing them is to just dry them out. They're mostly moisture absorbers with a bit of lavender - but once they're saturated (mmmmmmmmmm), they stop absorbing the stink and you're just left with the (now very old) lavender.
Worth doing this 2-hours before you intend to cook any food in the oven mind.