¿Es seguro el esmalte de uñas para uso repetido en clientes porque "no puede almacenar agentes patógenos"?

This is true. Esmalte de uñas can be used on multiple clients using the same cepillo and no other hygiene requirements.

This is because nail polaco is packed full of disolventes (how it dries), so is not an environment that any patógeno can survive (possibly with the exception of a hongos as fungal spores can survive many environments).

However, even though this is true, it is not in the profesionales de la manicura’ remit to work on uñas poco saludables.