Man (and probably Jim)Edit
With Man (and possibly also Jim), Geoff first promised a pencil to Man to get him to kill Woman. It is possible, however, that Geoff had already bitten him before this stage, and he certainly fed off Man's blood afterwards. Geoff also tied Man up and forced him to listen to light jazz.
Woman was 'killed' by Man with bullets to prove his loyalty to Geoff. However, he seems to have reanimated her at some point, probably just after sending Man to 'deal with' Fay Loren and Van Helsinki. Woman was under Geoff's control, in a similar way to Man.
While Geoff locks up Svetlana, he never attempts to use any form of mind-control on her, just 'swooping' down and carting her back to her pantry when she escapes. Presumably, this is because he thinks she is ay, and needs her 'untainted' for his Stevenage plot. This is supported by what he does to Fay when he finally gets his hands on the 'real one'.
Van Helsinki and Fay LorenEdit
With Van and Fay, Geoff does not bite or bother sucking blood, instead he simply straps them into his machine and mind-conrols them with some form of electricity. This works near-instanteneously.
Removal of mind controlEdit
Bizarrely, all the different kinds of Geoff's mind control were destroyed when the machine in his lair was broken. Word of St. Paul has theorised several different theories as to why this was the case.
The 'Machine King' theoryEdit
This states that Geoff needed the machine to continue to run his mind control on several people at once, and that when Svetlana destroyed it, the combination of the machine breaking and Geoff's powers waning caused the mind control to break. Thus the machine was essential to allow Geoff to mind control more than one person in the first place.
The Coincidence theoryEdit
Geoff released the mind-control reliant on his personal influence (e.g. Man, Jim and Woman) when he fled, as he needed his strength for the upcoming fight with Van. Van and Fay were freeed from the (totally seperate) machine-based control when Svetlana destroyed the machine.