I am just starting out on harmonica and got my harp two days ago. I am getting the impression that it is nearly impossible to bend on new harps. If so then how can I "break in" my harp?
To break in a harp, just play it. Do not play too loudly and after constant practise for a week or so, it should be broken in. Don't start bending straight away or it will shorten the life of the reeds
I think the need to break in harps is another debate like "Do wood combs sound better?" I don't really know enough to argue either side, but I lean toward "No need to break them in."