Just keep in mind it may work to reduce inflammation and decrease pain etc but it’ll mainly be a temporary reduction. As long as whatever is causing your chronic inflammation persists after the fast, it may not feel beneficial. I’d personally look into a low-carb/unprocessed diet. Orthopaedic surgeons anecdotally have seen pain reduction in post surgery patients on low carb diets before any significant weight loss and there are papers to suggest sugar and processed foods trigger inflammatory enzymes that cause pain in their affected joints.