In transit to join cruise ship

Hi There,

I will be joining a cruise ship in Shanghai where I will working as an entertainer (not in the crew manifest, hence I will be a guest on the ship) from the 5th of March to the 29th of April, flying into Shanghai on the 4th of March to join the ship on the 5th. The ship departs from Shanghai on the 5th to South Korea, returning to Shanghai every 5 days. Can I use this transit visa, as I will be not more than 24hrs every time I visit the country? I hold Brazilian and Italian passports. Thank you