I’ve never use/used any flea treatment for any of my dogs in my lifetime but once for ball spots. Never worked!
This recipe below is what I use n never had one dog with fleas, ticks n even mosquitos. I hike n walk often my dogs in the Rockies so I definitely know this works. BTW, All flea meds you see out there are made with chemicals even them flea collars. Like wrapping your dog/cat with pesticides. Not good. A few members do use this recipe with great reviews. Essential oils are powerful so don’t add more of one n less of the others. Also use a quality oil like DoTerra or Young.
14 oz of Witch Hazel
12 drops of Lavender
15 drops of Citronella
15 drops of Lemongrass