Pain worse almost a year after laminectomy/ disectomy.

i have one, but it doesn't pull hard enough... I'm really too big of a body for it to be effective. Big traction beds are thousands.....

You know yourself best, but my P/T recommended 70% of your body weight as a reasonable maximum. Moderators allowing, these are less than $500:

1) Saunders Lumbar Traction Hometrac - Deluxe
2) Teeter Hang Ups Spinal Stretch Back Stretcher.
3) Disc Traction Therapeutic Belt.
4) Inversion table.

There are other ways to decompress (Do a Google search). Did you try these in P/T?

1) "Static Back Position"
2) "Progressive groin stretch"
3) Have a massage professional "Release your psoas".
This is your primary hip flexor muscle. It attaches to all 5 lumbar bones .When it is tight, it puts constant compression on your lower back. So even if you decompress, as soon as you stop, the psoas goes right back to compressing your spine. So stretching will provide more LASTING results.
4) Al Meilus in Florida invented a robot which also releases your psoas.
I know people who have grown in height 1/2-1" by using this machine to release their psoas muscle.

Actually just sleeping at night by lying in a horizontal position will decompress your spine. If it does not, that means your muscles are tight. To prove it to yourself, measure your height when you get out of bed in the morning and then just before bedtime. You will find you have shrunk by 1/2 inch or so.

Just because you fall asleep does not mean you muscles automatically relax. I read that you have to be asleep for at least 4 hours before total muscle relaxation occurs and I'm not even sure about that.