All your 50 ways are illegal, and involve dealing with criminals who will take at least as much as the 25% the banks would, and no real guarantees the people in Mexico will ever receive the money. Or are they going to set up these transnational money laundering networks out of the goodness of their hearts? Nope, people will just continue to use the banks and give up the 25%.
Sending cash is illegal? Sending a money order is illegal?
And even if they were, the chances of enforcement would be near zero. Time to admit The Oompa-Loompa's plan isn't all that.