as horrid as it is, i understand why they do it in Thailand. sometimes, that's the ONLY way to get food on the table. but, those Plakats are pampered, and they stop the fight the moment one betta submits, and both are immediately treated for any and all wounds. they're kings of their jars, and are fed the best they can be fed, and are always soaking in a wonderful IAL bath.
the bettas we see on youtube? they're probably flushed once they're done. they sit in stagnant bowls after the fights, if the owner keeps them. infection sets in fast, i bet. poor babies are bought, only to die.