Empty bottle ? Get every Last drop out. Take it all apart and throw in some epsom salt. Citrus oils, On Guard, Melaleuca & Purify are GREAT! At getting the FUNK smell out !
Add that salt to your washer with your soap. (About 4 TBSP). It also provides as a natural fabric softener too.
Any calming oils are great for your skin & joints /muscles like Lavender, Frankincense, Serenity, Balance, Sandalwood - just to name a few. Add those empty bottles to salt. Use that salt in your bath ! Ahhhhhhh.
THEN! you have clean bottles to upcycle too & make mini sprays.
Get the most out of your bottles and use every little drop for your home and health.