Plastic bottles and heat do not go together.
Also very hard to get flavors fully out of a plastic bottle.
Wash thoroughly. fill with alcohol. let sit for 1 day and dump out then let dry while open for a day or two.
Usually gets rid of all the odors in the plastic.
Yeah; I just don't even bother with plastic any longer. When I did, I used the same flavor in the same bottles. But I have nice glass bottles now recycled from organic herbal tinctures and such. No worries there. Thank you though