if any consolation I chipped a flake of metal off my head in an injector port. I felt sickly in the tummy with remorse, cursed myself. I tried to suck it out, air blast it out through the removed exhaust manifold . Not sure if I ever got it all. I may have lost some compression in that cylinder. But she still runs fine 30-50k later and confident I shall get much more. At 11km/l fuel consumption, still happy.
best to get it out tho, probably the most thorough way is to remove the head which is a bigger job.
there is a youtubby of a guy kills a motor by putting sand in the cylinder