I have had a few lumbar ablations and numerous epidurals. I have gotten relief from both of them in a couple days. I never found them painful. I always had IV sedation for both procedures. The relief generally lasted about 4-6 months. I hadn't heard of ablations until after my first back surgery. My last ablation a year ago didn't help. I was told by the pain clinic that it can take up to a month to get relief. I didn't follow up as other things started to happen with my back. I had major surgery on my lower vertebrae mid May.
I would have another ablation if needed as I would prefer not to have an epidural because of the steroids.