So after researching this, I realize this guy is smart. So whats going on here is that by looking at the type if grass, it shows this this part of South East Asia floods a lot which is why catfish end up in burrows in land. During a high tide, the catfish dig burrows so they can survive when the tide goes down which is the time most people start fishing for them.

As for the Coke and mentos, they are used as a way to flood the hole with a ton of CO² (Carbon Dioxide) which due to it being a gas, as well as the amount of it released, it will force the fish out of the whole. To keep the catfish at surfave level, an egg is placed so this man has enough time to grab it before the catfish swims back down.