If you want to improvise a sidewinder, I'm reminded of a tale from the sixties: Members of an FAA Buccaneer sqn (801NAS?) aboard HMS Victorious wanted to convince any Soviet Spies who might be watching as the ship was about to transit the Suez Canal that their aircraft had sidewinders for self defence, which they certainly didn't have at the time. So they got hold of a number of industrial sized empty baked bean tins from the galley and welded them together, attached cardboard fins and painted the whole thing white. It was then mounted on one of the aircraft's wing pylons in full view of the shores for the duration of the transit... at least until one of the Commanders noticed it one day as he was on his way to lunch and ordered it removed!
The Buccs were finally wired for sidewinders by the 80s if not earlier. If those tins were full ones, would that not have counted as potentially rocket fuelled? Fairly explosive at least!