I fear none of those does help the network. If you run a host cache (pong cache) you have to make it public, otherwise others do not get any advantage. Those initial hosts you mentiond are not needed usually, all modern Gnutella servents get them automatically from (so called) host caches.

Best is install your Gnutella client and let it run 24/7 + share a lot of files + make sure your firewall allows incoming connections to your gnutella servent.

Greets and happy sharing, Moak