How affective is OxyGeneo with Tripollar handpiece for aging skin, jowls and double chin?

A combination treatment like the one described will benefit to some degree most patients. It all depends also on your expectations, goals, starting point of your skin among other factors. A proper assessment and discussion about your goals will give you a better answer. I would say though properly selected patients will benefit to a significant degree in most but not 100% of cases. 
Hope this helps and let me know if you need any further assistance.

A combination of Geneo skin rejuvenation facial treatments and Tripollar RF will certainly improve your skin health and tightness. Depending on your age, it may require a series of initial restoration treatments, followed by maintenance. If your goal is improvement of the jowls and sub-mental areas, I suggest adding RF-assisted micro-needling and higher energy RF skin tightening treatments.

Difficult to answer without proper assessment. For best results I find a combination approach is the best. What you are describing is very frequently the result of bone loss, fat pad displacement and volume loss, as well as loss of skin elasticity. We often use radiofrequency after dermal fillers - especially those that stimulate your own collagen like Radiesse and Sculptra - to achieve the best results. The most important factor for optimal results would be for you to get assessed by a Board Certified Core Aesthetic Physician who has done many of these procedures (Dermatology, Plastic Surgery, Facial Plastic Surgeon). Good Luck.