Prana:
Before you stretch your hip adductor which is your inner tights, stretch your psoas muscles, hip flexors first. Once your stretched your psoas good, then go back to your stretch machines. Here is some tips and some practical advice.
When you contract one muscle, the opposite muscles relaxs. If you want to relax your adductors, you will have to contract your glutes. By contracting your glutes while stretching your adductors will give your more range or motion and a better stretch. But this a passive technique.
I want to do try to adduct your legs together while on the machines for 5 to 10 seconds then release slowly and then stretch your your adductor a little more. Breathe! Rest a while wait out the tension. Adduct the legs together and of course the machine is resisting your legs to adduct, hold this contraction for 5 to 10 sec. then slowly release and stretch a little more. REst. Wait out the tension. You get the idea I hope.
Tell me if this help and keep me updated. If there is anymore questions let me know. Best of luck.
Mr. Bao
"A gung fu man, then, should be soft-yet not yeilding; firm-yet not hard." Lee Jan Fan