Update. I added a lot more content to the section for all other cute charm pokemon to help in making the decision of which cute charmer to use. I also added a section for other useful moves and the HM moves that delcatty can learn. This should further help in making the choice.
Take note: While Delcatty is the optimal cute charmer due to the myriad of things it can do such as pay daying, horde clearing for the main EV hordes, cute charm, and a decent catcher mon, Milotic and Lopunny are also two very viable options. I personally like Milotic the most due to the increased bulkiness and Rache has also provided a fantastic moveset for it for thinning out a horde when using it for shunting.
I also re-confirmed with the devs and cute charm does not work for alphas