Most of the induction methods are a load of old shite imo. The baby will come when it is ready, although I don't doubt that if the baby is good and ready some of the methods will help move along the inevitable.
Clary sage - can be good for when established contractions slow down. I sniffed it our of curiosity when very pg with ds2 and it gave me wicked BH's but nothing else.
raspberry leaf tea - tones the uterus, it will not do anything to bring on labour.
Sex - this may (or may not) have helped ds2 along the way.
Reflexology - this may (or may not) have helped ds1 along. I had it done on the Friday and started contracting that night - but I was 9 days overdue at that point.
Sweep - had one with ds1 at 40 weeks. My cervix was in no way favourable for a sweep, it was bloody painful and done fuck all. I wish she had told me it wasn't favourable because I would have told her not to bother - especially as a sweep holds the risk of introducing infection. I wouldn't say no to a sweep again, but I would only have one if my cervix was favourable.
Bumpy car ride - maybe this would work if your waters are bulging? But would you want to break your waters ahead of when the baby is ready? You run the risk of infection.
Castor oil - Some say it works but apparantly it is very painful and who wants the shits in labour?
Pineapple - I never heard anyone say that this works and if the theory is correct you have to eat about 12 or something stupid.
Curry or anything spicy - the theory is to eat something that gives you the shits, that way the spasm of the bowel stimulated the uterus to contract. See my comment about castor oil!!
There you go, my bar-room opinions on natural induction methods 
In short, save yourself money, effort and upset by not bothering. You'd be better off spending the money on some decent chocolate and a facial!!
lisMcA - my feelings towards sweeps aside(!), most MW's would not give you a sweep before 40 weeks.