This is the most important step to ensure a proper bond.You want to remove as much of the natural silicone oils, lube, etc. as you can, so there is nothing between the toy’s surface and the Peg Away Putty®.
Do this with a really good grease-lifting detergent like Dawn®. Many other soaps or natural cleansers won’t be effective enough, but Dawn® is inexpensive and it works well.
Use the detergent and gentle mechanical action to work the surface and lift any oils that are present. You can simply use your hands and squeeze and rub the entire surface. Using a soft cloth or gentle brush is also effective, especially on toys that have a texture, like a tail. Rinse well with warm water and repeat the washing process.
Make the second rinse very thorough, and be sure to rinse any soap residue from your hands as well, as that could transfer onto the toy and prevent a bond or inhibit the cure. Pat dry.