When i have had problems that need to be treated in that way, i have always found that as often as possible works best! But usually with other commitments that translates to about twice a day, morning and evening. stretch, then massage, then ice is the way i find it works best.
foot stretch - Sit in a chair and cross one foot over your other knee. Grab the base of your toes and pull them back toward your leg until you feel a comfortable stretch. Hold 15 seconds and repeat three times.
calf stretch - normall standing calf stretch will do fine.
You can massage the arch of your foot effectively with a tennis ball, roll your foot over the tennis ball concentrating on any tight spots. this can be done quite happily while watching tv!
Calf muscles I find are massaged best either by someone else, or by using a foam roller (one of those things that is worth trying to borrow first before you buy one - maybe someone at parkrun will have one you can borrow) or even a rolling pin!
I am not saying that you should stop wearing orthotics and I am not saying that you should not try barefoot running, that is not for me to advise on, but i do think that treating the muscles in this way should see some improvement.