Moxidectin worked for me. Basically, quest Moxidectin (not Quest plus) - took the amount appropriate for a horse of my body weight. https://www.amazon.com/Quest-Wormer-Equine-Moxidectin-0-4oz/dp/B00XER1QTK
It takes about 3 days to start feeling it and 3 weeks to kill them all - but please know that your experience might be different and you are taking unknown risks because there are only a handful of studies.
Moxidectin in humans 1.
Moxidectin in humans 2.
Moxidectin on Amazon
Gentrol SDS.
Precor and fish.
Even if Precor and Gentrol are relatively safe for fish, they still include a solvent so it's good to have good ventilation when applying it until the solvent dissipates. I already had a fogger for mold remediation. I vacuumed the heck out of the carpet and upholstery and then fogged it per the instructions (volume per square foot).
Someone performed a study and found that fleas don't survive vacuuming so there's no reason to treat the vacuum cleaner as biohazard afterwards.
When we had fleas, my parents brought them from their place to mine, but I don't think any made it to my sister's. Only my sister and I took moxidectin and along with the Gentrol it was enough to kill them off at all 3 places. I give moxidectin the most credit.
None of us had furry pets so it was probably due to raccoons living under the shed. We commemorated our victory in The Second Flea War with flea plushies.
The one I used was Quest gel by Zoetis which I got from amazon.com (so it came from the american amazon). But the one you linked to is the same brand, practically the same name so I'd say its basically the same and probably good to use. I'd probably buy it if I needed more.
The one I got is "currently unavailable" now anyway...
Here is what I used: https://www.amazon.com/Quest-Wormer-Equine-Moxidectin-0-4oz/dp/B00XER1QTK
Well, i dont think you have skin cancer, if you believe so you should go to a doctor. But anyway NO you dont need BB too, just go buy that damn moxidectin. Here is a link: https://www.amazon.com/Quest-Wormer-Equine-Moxidectin-0-4oz/dp/B00XER1QTK
This one cured me in 2 weeks. And i recommend doing BB at the same time to increase your chance of being cured from 95% to 99%. I promise you it will work.
https://www.amazon.com/Quest-Wormer-Equine-Moxidectin-0-4oz/dp/B00XER1QTK
This it the one I bought
And this one without plus without praziq from America is out of stock https://www.amazon.com/Quest-Wormer-Equine-Moxidectin-0-4oz/dp/B00XER1QTK