Agreed, it almost doesn't matter what type of ground you walk on, water can be especially good because of its conductivity.
I know, most festivals we would be insanse to walk barefoot. that's why I love festivals so much where people realize that their trash will not only make the festival experience worse for anyone else, but ultimately for themselves, giving silent permission for other people to throw their trash on the ground as well.

Have often wondered about the Earth soaking up all the stuff from people's feet. But I guess the weather cycle just cleans itself hehe