In a bowl, stir together pickles, celery, scallions, tuna, garlic powder, white pepper, salt, and black pepper. Break tuna into chunks as needed. Mix in avocado sauce until thoroughly combined and desired consistency is achieved (if you want it chunky vs. more well mixed).
Store in an air-tight container with saran wrap covering the surface to ensure avocado sauce doesn't brown. Will stay in the fridge for approximately 1 week if stored this way.