Is OM MA NI PADME HUM flag useful? May I use this Tibetan flag above door and will this protect house from negative and bad energy?
I know importance of chanting OM MA NI PADME HUM.
So is it helpful or just feng shui thing?
I thought to ask before having one above the main door.
If it helps guard your and others' hearts as a summons to mindfulness it is quite useful.

If it is intended to ward off a jet falling from the sky it is not so useful.

If you are looking for a guard against "Negative and bad energy (black magic)" you are looking for a place without fear.