The problem with inversion therapy for back pain is that it also stretches your knees and ankles and neck, and most people cannot handle the extra blood pressure to the head for more than a few minutes.
If easy and inexpensive spinal decompression is what you're looking for, there's a new product called 'Spinal Stretch', which even has top neurosurgeons endorsing it.
It's a strange looking contraption that you use lying down while reading a book or watching TV. The thing only weighs 4 lbs and is fully portable.
My wife was crippled by sciatica and a week later was 100% better.
Something you won't hear from most MD's—you’ve also got to drink plenty of water to keep your discs properly hydrated.
Best of luck!