There are multiple sites mentioning some cheats that never ever worked for me:
Source: Cheat Codes cheats for Hitman 2: Silent Assassin on GC
Fly and Attack:
Type 'IOIAIR'
Play as Father Vittorio:
Type 'IOILAWS'
Source: GamePatchPlanet - Hitman 2: Silent Assassin Cheats, Codes, Trainers, Patch Updates, Demos
All guards slow - WININGMAN
Toggle Punch - IOIMEGAZ
Toggle Silent Assassin - IOIASSIAN
Cult member clothes - ITNOTFORME
Rocket launcher - IOIFIRE
All pistols - IOIEQPPISTOL or IOIEQPGUN
Toggle fast running - IOIROCKET or IOISPEED
Fire mod - IOIDRAGON
Toggle Invisibility - IOIINVS or IOICANTSEE
Fast gun speed - RATPOWER
Play as Father Vittorio - IOIFATHER or IOILAWS
Tried this with 1.01 and 1.02 no effect afaik there is no public release for 1.0
So is this all fanfiction? A fking rocket launcher? lmao