Your breeder might have some feeding tips for you. I would think it is best to clean it before it dries. Many birds like spraying with a misting water, maybe that would make cleaning it with your fingers or a cloth easier
My cockatiel came to us (from a bird show where he insisted on coming home with me) from a breeder with so much formula stuck on his face feathers in chunks and dried over time that it was pulling the feathers out. My husband turned the water on in the bathroom sink, tepid and low (not gushing out) and wrapped Freddie up like a burrito with just his head sticking out and just washed and washed until it came off. Freddie was NOT happy about this experience, but it had to be done. He got over being mad in a couple of days.
Quaker Clyde; tiel Freddie; Rocky 'Too; dog, Jack; too many fish to list.