Deciding to go with drilled vs non-drilled is based solely on personal preference. One is not better than the other.The drilled egg is designed to thread a piece of unwaxed, unflavored dental floss or silk string through it in order to explore 'retention training.' This is a practice of holding the egg inside and gently pulling on the thread using your pelvic floor muscles. Retention training helps to strengthen the pelvic floor, increase energy, heal pelvic area trauma and can help to make for longer stronger orgasms. Having a drilled and threaded yoni egg also lends to easy removal. Be certain to clean the hole thoroughly before and after each use with our handy yoni egg cleaning brush.The non-drilled yoni egg is completely intact. This makes it easier to clean as there is no hole. However, without the hole, the types of exercises you can practice with your egg are somewhat limited. Remember there is no way for the crystal to get stuck or go ‘up’ into the body. The cervix/uterus at the end of the vaginal canal will block this from happening as it is a closed system.