Here' what I did-
1- Synced ipad and removed all media, email acct, contacts etc, anything you can sync with iTunes, I unsynced. (You can not use the on-ipad "Erase content" this will brick it and you have to restore to 5.1)
2- on iPad I went thru everything in Settings and tried to reset or erase my settings and acct names, including email if you set it up.
Is it safe? I don't know for sure.