This device is still being sold online (the one from the second video), although it was invented a long time ago.
Other devices may produce too much ozone, and they MUST NOT be used continuously, especially in an unventilated room.
And other devices would be more accurately called ozonators rather than ionizers.
Ideally, a room should be ozonated as follows:
Turn on the ozonator and close the door and windows. Leave the room for 10 minutes.
Come back in, turn off the ozonator, and ventilate the room.
That’s how.
Ozone really does kill everything, especially bacteria. It is a powerful purifier.
But you must not breathe it continuously.
In small doses, it can be used periodically.
Therefore, in my opinion, among the ionizers available for purchase, specifically ionizers rather than ozonators, the one from the second video is suitable.
They are made by Siberians from Novosibirsk. By the way, a lot of interesting things come from there. For example, Buteyko found refuge there for a long time... while he was banned everywhere else.
Be sure to watch the first video in full. It tells the story of how the device was created.
And I’ll repeat once again: the device’s first inventor was Chizhevsky, Tsiolkovsky’s student.