I have a 3 phase approach, stopping when I have removed the desired amount of mould:
1) Use a cotton bud wetted with spit. If nothing else this will clean up the metal part of the hands. It looks like yours are too far gone for this.
2) Gently rub with a pencil sander - not sure what the proper name is but it is essentially a propelling pencil where the lead has been replaced with a sanding stick. I take this stage very slowly to avoid scratching the metal part of the hands as any damage here cannot be undone. The aim is to remove the top layer of lume which contains the mould.
3) Finally, if the above methods have not worked, I remove the lume, clean the hands and relume.
I am sure others have different approaches but this works for me.