Mould in fuel filler flap area

[alps26]

Any tips on removing mould from the fuel filler flap area without it discolouring or damaging anything?

I can see patches of mould on the fuel cap and some on the surrounding rubber. It looks like those black patches you get on silicone sealant rather than anything furry.

I try and clean it every wash with car shampoo (GTechniq G wash) and a detailing brush but it doesnt really work

 

[pelhamsdetailing]

Tried an APC of any kind? Something with grunt, like koch chemie or bilt hamber surfex HD. A citrus cleaner with actual Limonene in the ingredients historically has good cleaning strength, too.

 

[alps26]

Tried an APC of any kind? Something with grunt, like koch chemie or bilt hamber surfex HD. A citrus cleaner with actual Limonene in the ingredients historically has good cleaning strength, too.

Thanks, I've got some KC Green Star mixed up (1:15) so I'll give that a go. First time using KC stuff but impressed by it!