Ab King Pro is a big time waste of money. I bought it and eventually developed back pain due to it's poor posture positioning. Better do your abs workout on floor, or a softer simple flat bench if you have one.
There ain't a special formula to ONLY reduce waist, all the fats from your body are going to be reduced and eventually the stubborn fat ( i.e., your belly and love handles, the toughest *** fats) Follow this routine and within months InshaAllah you'll see the difference.
- Walk BRISKLY for 1 hour daily (preferably download any book of your interest from audible. com to your mobile and start getting knowledge while you lose weight
)
- Cut your calories count to around 1500 calories per day.
- Split your meals into small portions ( if you are gonna eat 3 rotis in a day, divide em into 6 times)
- Avoid fats, prefer eating vegetables, fruits, and drink water, a LOT of it.
- Join a gym if you can, working out your muscles would help the rest of your body get toned while the walking/jogging/cardio would help burn your fat.
Basic reason for bulging belly is Eating LARGE portions of food at a time + sitting mostly whole day long + not doing any sort of workout at all + late night meals, i.e., sleeping immediately after dinner. try to avoid this as much as possible .
There are some "crash" programs for losing weight within weeks, but i would not prefer you to follow them because they are quite hard to follow and eventually you'd end up quitting this BS altogether
so slow and steady wins the race, just make walking/jogging and eating healthy + less quantity at a time your lifestyle and enjoy the happiness and benefits of a faster, leaner, quicker and attractive body 
Good Luck !