Review on Silicone Egg Separator by Tovolo for Effortless Yolk Removal by Ben Rodriguez

Suction power is not easy to control. There are problems with medium and large eggs, because the yolk leaves a gap around the hole, and the egg white can also be absorbed. If you want to leave the whites and mix in the yolks, that's fine, but you'll likely suck out some or most of the whites along with the yolks. On the other hand, if you only want to use the yolk, it will have some protein contaminated with it, and since there is a 50% chance that the yolk will break, especially if the onion also contains protein, you may need to do something or start over.