240 hours visa free transit in China

Yes, it would, however, certain conditions have to be fulfilled:

1. You can take a ferry from Hong Kong to Shekou port in Shenzhen or to Nansha port located south from Guangzhou. You cannot take a train because taking a train from Hong Kong toward mainland China is not eligible under 240 hour visa free transit.
2. Before taking a ferry you will have to buy a train/boat/flight ticket that will take you out of China to a third country or eligible territory. Eligible territories are Hong Kong, Taiwan and Macau, however, you cannot return to Hong Kong, but to any other country of this world or to Macau or Taiwan. Simply speaking, the immediate points before and after your mainland China visit have to be in two different countries or eligible territories.
3. The time you have at your disposal is 10 days under 240 hour visa free transit scheme and you are allowed to travel across major part of China with several exceptions, but those exceptions are not usually on a well beaten tourist routes.

Have a nice journey.