I have a couple of people in the local area that want to buy some of my Pekin duck eggs, I get 3 per day. I have 1 drake. 1. If I clean them will they still hatch? 2. How much does a fertile duck egg sell for? 3. What temperature do they need to be kept? 4. When is the soonest I can candle to let a person know they are fertile? Or do I just give them the eggs to find out for themselves? Thanks for your help.