Yes, there is some merit to using coke as an alternative method for unclogging a shower drain –albeit it is not the best means for doing so.
Coke does possess a reasonable amount of corrosive power, so you could choose to pour some down a drain and allow it to work its magic before adding hot water for the best results.
The fizzy drink is packed with phosphoric acid, which can effectively tackle buildup that has the potential to clog your drains.