Coming from a fatty, my inner thighs held onto the fat. Best to increase overall lean mass of upper thighs to sort them babies out.
As with everything else, they will lean up better as bodyfat reduces. Best to think of targeting the thighs as opposed to isolating the muscle.
Best exercise I have found that smashes the upper thighs is UDLs with a decent wider stance (like sumo deadlift), squats and Lunges. Lots of them.
I never use machines either.
Just my 2c worth.