Can detox help with fibromyalgia?

Possibly. Increasing doses of opioids to try to chase the pain, unsuccessfully, can sometimes result in “opioid induced hyperalgesia”. Typically, fibromyalgia does not respond well to the pain managing aspects of opioids, although it sometimes improves mood and spirit by reducing the suffering aspect of pain. If you have been taking increasing doses of opioids without improvement, it is time to taper off.
Not likely.? If "detox" might ameliorate fibromyalgia. It is not expected that detoxification would lessen the intensity of FM, which is a condition of widespread muscle spasms & soft tissue strain/deterioration secondary to deconditioning from resting after a mechanical injury &/or prolonged illness-convalescence. Increased muscle mass/tone is needed & protein depletion w. detox would be counterproductive.
Fibromyalgia. I am wondering what sort of detox you are talking about. Please clarify and I'd be happy to help you.