Deportation question

I’ve been seeing the Guantanamo detention center being built on the news. And I seen how low level risks(no criminal record other than illegal entry) have been taken there even though it was supposed to be for high level immigrants. Theoretically, if they stopped a low risk immigrant and wanted to send them to this base, would they have the option to voluntarily deport themselves to their country instead? Because this concentration camp seems far worse than just going back to their home country