That video is way too long and I don't think he's acclimated that many fish before.
In the usual case where there's nothing wrong with the fish or the water in the bag - for example, when you go to the pet store and bring home about any mainstream fish in a bag - you can very safely remove the fish from the bag water and add him to your tank.
If you have reason to suspect the health of the water or fish - maybe you buy sight-unseen online - then it could be worth a 10 minute drip acclimation.
This means put the fish and the bag water in a bucket or something - ideally where the bucket can be floating in tank water. Use a piece of airline to creat a slow drip from your tank to your bucket. After about 10 minutes, remove the fish from the water and put him in the tank.
Any more time than this is unnecessarily going to stress the fish by having him in a tiny container with increasing ammonia levels...and there's very little upside to longer times.
-Matt