Pen marks are stains, so they need to be sunfaded. That link that Strawberry supplied has some instructions, but be sure to check in often, as sunfading is much more practiced on G1 and some have reported issues while attempting to sunfade G3.
What about sun fading G4?
The Sard Wonder Soap had a visible effect on my G3, reducing the stains so with the remaining ones I just gotta keep applying.
With my G4 pony, the sard wonder soap didn't have any visible effect, other than lightening up his skin so using it to remove stains isn't an option.
Post Merge: February 19, 2019, 08:02:16 PMi curl hair using straws and bobby pins. let it dry, then pull the straws gently out.
boiling water and a fish knife against the plastic "pores" gets the ingrained dirt out
strong chemicals like acne cream or bleach are a NEVER
So I'm guessing wet the hair, maybe condition it and put the hair around the straws, letting it dry out?
I can understand the boiling bit, but may I ask what a fish knife is? Never heard of it.