Once the flesh cut away, you can hold your watermelon rind in your hand and, using a vegetable peeler, careful pare away the green outer rind. You want to be left with just the white part on the outside. The green part will never get soft during the pickling process.
Now for the fun part - the pickling!
Gather your materials: white vinegar, sugar, cinnamon and powdered cloves.
Put your ingredients together in a large pot (I used a 5-qt dutch oven) and bring to a boil.
Pour your boiled syrup into your large bowl, just covering the watermelon rinds. Cover and let them hang out in the refrigerator overnight.
On the second day, drain the syrup back out into a large pan and bring to a boil again. Then pour it back over the rinds. Cover and let it chill out, just like the first night.
On the third day, put the whole mess into a big pan and bring it to a boil. Remove the rinds to your prepared jars, then add your hot syrup. Process your cans....and you've got pickles that will last the rest of the year!