PysankyUSA offers you a large selection of 'Water Cleaned' only eggs.When preparing to work on eggs (except Duck Eggs, only water should be used, and never any rough rubbing) they should be cleaned with a paste of baking soda, rinsed in clean water, then dipped in white vinegar and dried. Some eggs like ostrich or rhea may require etching the surface to remove the sheen, a safe format is to soak the egg in vinegar to create a slight etch, then sand with super fine sandpaper. I also sand my goose eggs before working on them , as I prefer a smooth surface. Some artist prefer to clean their eggs with a short acid bath (Muriatic Acid, The Works, or Acid Magic) When doing this make sure you are wearing eye protection, gloves, and are in a well ventalated area. Repeat: Remember for proper dye coverage, the only thing to ever touch a duck shell is water, after rinsing the duck egg with water, do not let any shell stains bother you, as most likely they will not be noticed when the dye work is done. It is the membrane on a duck shell that takes the dye colors, once this membrane is disturbed you will only get pastel colors.When working with any eggs store bought or from my store, always block up the hole and reclean them. With the new 'Magic Sponge' it is nothing more then a micro fiber and will break down when no longer usable, tip the sponge into a slury of baking soda and scrub the egg (avoid duck eggs) Avoid leaving these sponges where children or pets can get to them, please read the warnings on the box. Once I scrub an egg this way. I give it a good rinse, and then dip it in white vinegar. it is ready to work on. Grocery store eggs are mass produced and cleaned, you will often get ring marks on a shell, this is where the shell rests in the drying rack. Also many store bought eggs now are sprayed with a light layer of vegetable oil to give them longer shelf life.Remember etching a shell with acids may cause it to only take colors in a pastel format.Also Chlorine Bleach will cause shell to not take color. If you follow the cleaning directions I have listed here your dyes should work with all eggs.