UsingCheats - AdmiralCurtiss/swiss-gc GitHub Wiki
How to
Cheats are stored in a Qoob based file format, they may be edited/updated using the included cheats editor. You may convert action replay codes using GCNCrypt and then add those too.
Swiss comes with a embedded cheats database but if you have an updated one, place it on any device that Swiss can read from and select it in Swiss to read the cheats from it.