Had a look at the specifications for Australian Hoop Pine and it seems it has a wide variety of uses, some of which involve structural penetration by steel members. Subsequently, it seems the users in these applications were not concerned about corrosion due to the wood. However, this does not mean that it is suitable for our sword related purposes, just that it might be worth experimenting with, if that is all you are able to get. In the USA, basswood, alder, as mentioned, as well as poplar, seem to work well. I have also used rock maple successfully.