How do I clean a G4 pony?

[FlickaFriend]

Today I've acquired a small collection of G4 ponies (for my daughter, I really only like G1s). They could all do with a mini spa day but I have some questions:

Can they be submerged or are they like G1s where you should be careful not to let any water inside?
Are they hollow like G1s?
Do they have a tail washer and can they ever get tail rust?
Can you take them apart like a G1?

They are my first G4s and the first I've seen IRL. They're kind of cute but their tails are a bit sparse and they don't really look like the characters in the programme... It's a shame they couldn't individualise their bodies a bit more and the eyes aren't quite right on Twilight (too seductive) and Rarity (no bottom eyelashes) (grumble grumble! I guess I am a die hard G1 fan! Also got a lovely Majesty today with matching white head and body, yay.)

[Leave a Whisper]

Same way you clean any other pony that doesnt have special requirements. Shampoo and condition hair, hand soap or dawn for body.

Magic eraser can sometimes help get marks off.

[Goanna]

I'm pretty sure they all have metal tail washers, yep. Although I haven't seen a G4 with tail rust yet...

Yes, their head can be taken off. I haven't tried it myself, but I've heard that their heads are particularly hard to remove.
And yes they are hollow!

[Baby Sugarberry]

Do not submerge in water unless you are both familiar and willing to disassemble G4's.  There's no other guaranteed way to get out all of the water and moisture.  Wiping them down with a damp cloth / soap will take care of most grunginess, hair can be shampooed and conditioned - try to keep from dunking them and shake off the water after rinsing.  Basically treat them the same as G1's.

They can be taken apart but it's not an easy task.