FenrirWolf is correct, and WiiShizza helped me out the other day. In the Homebrew Browser, under utilities, you download codedownloader and wiicm (code manager). Use codedownloader to browse for a game, and download the cheat. This creates a folder on the root of your SD called txtcodes, where the text file is stored. Then use the code manager to pick the game, activate the cheats you want, press home and choose to save .gct when prompted. This creates a codes folder on the root of the SD where the custom cheats are stored.
Launch the ULTIMATE LOADER, toggle Ocarina "on" and it should work perfectly.