Spike particles would be excreted in sweat, urine, feces, and other body fluids - if they were not destroyed by the macrophage system within the body. They might be found in skin particles shed as part of normal wear on the skin. It would make an interesting research project.
Got any grant money? I can get the scientists.
I believe it would be extremely unlikely to transfer spike proteins through breath exhalations. Maybe sex would do it.
Spike proteins have been found in the lymph system up to six months after a COVID-19 mRNA treatment. I have not found any research that has actually discovered spike proteins in other body fluids or skin cells.
I am fairly certain that it is not happening. Not too worried about getting spike cooties from my vaxxed relatives.
I am more concerned about catching the latest variant of COVID from them. Or maybe just the ordinary flu.
Thanks.