I rinse the guts and seeds in plenty of water with vigorous stirring and then strain and lay them out on a surface (cookie sheet). The rinsing should release the seeds from the stringy stuff and then you can start picking out the "guts". Removing the guts from the seeds works better than trying to removed the seeds from the guts (if that makes any sense). After you have picked out most of the stringy stuff, another rinse and strain usually finishes the job.

I use an ice cream scoop to remove pulp and seeds from pumpkin. I separate pulp from seeds with my fingers, and running water to finish cleaning the seeds.

I think a large sturdy metal spoon is about the best tool there is for that task.

You might find some of these tools helpful:
http://www.food52.com/blog/4702_6_unlikely_pumpkin_carving_tools

And we recently did a video with the guys from Maniac Pumpkins!
http://www.food52.com/articles/4724_how_to_carve_a_pumpkin