I had some G2 recently and they were marked up and their hair was knotted. Mr. Clean magic erasers actually clean very well, it cleaned hard marks on my G2 very well. I would just watch out for the symbols, the paint used on this year pony can be rubbed off easily.
As for the hair, I use Garnier Fructise dry, frizzy and unmanageable hair conditioner and it brings back the softness. I have also heard Pantene has been proven to help get frizz out of hair. I hope this helps!