7 day trip to Shenzhen from UK Visa Requirement

Hello people,

We are a group of 5 travelling to Shenzhen in September 2019 and wanted to know whether we could enter Shenzhen with 5 day VOE’s even though our return ticket departure would be 7 days away. We were hoping that by going to HK for one night we could get a new visa on our way back after a few days. Would that work?

Any advice on this would be appreciated...thanks.