A couple of non-pharmaceuticals to consider:

1. Nasal rinses. You can use saline rinses (I prefer hypertonic saline) and adding a small amount of baking soda to alkalinize the rinsing solution has even greater benefit. Or you can purchase packets at any drug store. I work in a hospital and have used nasal rinses a few times per week. Haven't gotten sick yet. [Fate don't smite me, I'm trying to help fellow travelers].
2. Quercetin. Taking this results in a 40% improvement in outcomes from severe infection and is 93% effective in preventing COVID infection when used as prophylaxis. Read more about effective treatments at https://c19early.org. It's a great site to show what has worked and what doesn't work (like convalescent plasma). No medical advice, but I also think these treatments have a similar effect on all upper respiratory viral infections - not just COVID.

Use smoremail.com or mailbait.info for the e-mail addresses that get through. If multiple spam messages come from a specific domain, look up the domain on whois.com and report to the domain registrar. May not stop them all, but fun to fight back a little.

This language is straight from the FTC's complaint:

A. Vitamin D: The Truth v. Defendants’ Misrepresentations

25. Wellness Warrior Vita D is an ingestible product sold in softgel capsule form. Each softgel of Wellness Warrior Vita D contains 5,000 IU Vitamin D3 (cholecalciferol) and unspecified amounts of “[o]rganic, extra virgin olive oil and softgel (bovine gelatin, vegetable glycerin, and purified water).” The Wellness Warrior Vita D product label directs users to “Take one softgel daily, or as directed by your healthcare practitioner.” Wellness Warrior Kids’ Multivitamin also contains Vitamin D.

No Studies Prove That Vitamin D Prevents or Treats COVID-19

26. There is no competent and reliable scientific evidence that Vitamin D protects against, treats, or prevents COVID-19.

27. There are no published studies that prove that Vitamin D protects against, treats, or prevents COVID-19.

Now go to https://c19early.org/d. It lists more than 100 studies showing that Vitamin D improves mortality, recovery, odds of ICU admission, and viral clearance in COVID patients.

The FTC's complaint is void on its face.

If people want to purchase overpriced Vitamin D with special extra virgin olive oil, that's their problem. Studies show that Vitamin D does treat COVID and this guy may be a huckster, but he didn't claim anything illegal.

Not sure what you're searching for, but here is my go-to list: https://swisscows.com/ https://andisearch.com/ https://www.etools.ch/search.do https://gibiru.com/ https://metager.org/ https://searx.space/

Swisscows.com/ Have been using only this search engine for years. Also will use Startpage.com on occasion - this is an aggregator