I have used all the above methods and they have worked. A couple months back I splurged and bought the Stampin' Up! cleaning thingy. It looks like an over-sized stamp pad. When you open it up it has felt (??) on both sides. You spray one side with cleaner and the other side is dry. You rub your inked stamp on the wet side and then on the dry side - clean! I really like how handy it is, but it is a bit pricey ($14 or so??) but to me it is worth it.
Sorry for the poor description, maybe someone can explain it better or post a picture..
Jill