I have had 2 post dates babies - it seemed tortuous at the time! I tried acupuncture and I do believe it worked, I used homeopathics, sex, using an epo as a pessarie a couple of times a day (acts as a prostaglandin), curry, walking up and down the stairs (only served to exhaust me!) I even caved and did the castor oil - I wouldn't recommend that to ANYONE I was pooing through the eye of a needle all night and no baby!
Basically as you know, natural induction methods (and often artificial ones!) don't work until you and your baby are ready. Try some visualisations, talk to your baby...
I haven't been much help, sorry!