USB Loader GX has Ocarina functionality built in to it. First enable Ocarina in global settings, then go into the settings for the individual games, download the cheat list, enable the cheats you want, then click "create cheat file" (It's not actually called "cheat file", but I can't remember it's real name) then start the game and you're good to go.
Be wary that some games have multiple versions, and cheats can cause problems for some versions. Fire Emblem Radiant Dawn for instance suffers from frequent freezing if you enable cheats in version 1.01. Loading Monster Hunter Tri's cheat list freezes USB Loader's menu due to the sheer amount of cheats for the game.