SEOUL: Knowing how quickly public disgust can wither a strike, protesting unions are sending their charges back to work--for free. As part of a "Day of solidarity with the people" arranged by the outlawed Confederation of Trade Unions, striking auto mechanics provided free tuneups in 12 South Korean cities, and some nurses and hospital workers set up tents offering free blood-pressure checks and services for the elderly. The confederation also promised that thousands of striking workers would hit the streets with brooms in a cleanup campaign, while others would help dig out remote villages snowed in by a recent storm. Throughout the spreading strike, union workers at subways, phone companies and cargo docks have been directed to stay on the job for fear of raising the people's ire; hospital workers also have remained to staff emergency and operating rooms. Home Minister Kim Woo-suk warned that if the unions prolong the protests, the "government has no option but to take firm action." For now, though, the Seoul government will let public opinion determine the strikes' course. It is a war that unions seem to think they can win.