Separate seeds from pulp and rinse under warm water. Pick out remaining pulp. Shake off excess water, place on a towel, and roll up. Let dry in a warm location for 2 to 3 hours.
Preheat the oven to 300 degrees F (150 degrees C). Line a baking sheet with a silicone mat or foil.
Mix dry pumpkin seeds and melted butter together in a bowl. Sprinkle on garlic salt, onion salt, and paprika. Spread on the prepared baking sheet.
Bake in the preheated oven until golden and crisp, stirring halfway through, about 45 minutes. Let cool and store in an airtight container, but they taste amazing warm, too.