Are there any at home remedies to dull the pain from sacroilitis?

Yes... If it's acute, rest for the first 1-2 days. This controls your symptoms and reduces any swelling in the area of pain. Apply heat or ice to the involved area. In general it is a good idea to use ice for the first 2-3 days, then use heat. while sleeping, try lying on your side, curled up with a pillow between your legs. When sleeping on your back, place a pillow or rolled towel under your knees.
Determine the cause. Need to r/o rheumatological basis for pain, post traumatic. If related to strain or everyday activities can try heat , stretching, tart cherries, glucosamine. Might need pt or cortisone injection if no improvement.