I simply don't like to use a piping bag to fill deviled eggs. It makes it look too "purchased" rather than coming out of your own kitchen. Deviled eggs are a rustic comfort food appetizer. Use a fork to pat the egg mixture into the egg white shell. Mound it nicely. You may not have enough filling for exactly 20 deviled egg white shells, which also give you a chance to pick out the best looking white shells for presentation. Use a spatula to get every last drop of filling out of the bowl. One little spatula full will fill an extra egg white shell.