That “snake oil” you are talking about is used around the country to purify water.
All the water at your tap has been treated by UV Light.
It’s cheap, practically free, and it can’t be patent.
Thus, why the Big Pharmaceutical (modern day Quacks) companies DO NOT want you to know about it.
They don’t want to let a crisis go to waste. That could be billions in their shimmy pockets.
Pathetically Hilarious - you sound like a commercial for Blue Emu.
UV is tricky. It will make most plastic materials brown and the discoloration is permanent. UV C is extremely hazardous and not to be trifled with.
And it is effective only for line-of-sight where any critters not in direct illumination will live on. Thats what the makers of these robots DO NOT want you to know about.
Not all water treatment uses UV some either uses chlorine or both UV and/or chlorine to kill bacteria from stage 3 of the treatment process.
UV can be used to purify blood by cycling it through a UV source and putting it back. It kills the germs in the blood.