Boil the seeds:
A few years back I learned this trick about boiling the seeds in salted water. It helps to truly get them clean and makes them easier to dry out after. So boil your seeds in salted water for 20 minutes in a pot. Drain them in a colander and then move to the next step.
Dry out your seeds:
There are several ways to dry out your seeds but the best way is to pour them out onto dry cookie sheets and let them sit and dry for 24 hours. Don't let them clump together, make a single layer so they dry out faster. If you want, after about 12 hours, you can shake the pan a little to get them to flip and spread them out again but that step isn't necessary.
Prepare Your Seeds:
In a small bowl, combine the garlic powder, salt and creole seasoning if desired.
Toss the seeds into a large bowl with the butter and garlic/spice/salt.
Spread evenly on a cookie sheet or two.
Preheat oven to 300 degrees. Bake seeds for about 30 minutes. If you like a crispier shell, you can add an additional 15 minutes, but please keep in mind, that all seeds are created differently and there are many variables to how long they need to actually cook - moisture in the air, season, how humid it is outside, etc. I usually bake about 25 minutes and then watch them after that, stirring occasionally and the longest I've ever gone was 45 minutes but on average, 30 is the magic number for me