TL;DR: yes, import a foreign configuration.
Recent Dell PERCs are rebranded LSI/Avago/Broadcom MegaRAID SAS controllers, and therefore all LSI techniques and tools apply. To name a few: megacli is for configuring anything (creating/removig/reshaping RAIDs, replacing disks, reading logs, updating a firmware of the controller and so on), it's old and obsolete, but it still works, with storcli being a modern replacement; smartctl can query disks behind a controller even when disks aren't available directly in the OS, but this feature only works with Linux megaraid_sas driver to my knowledge. These tools are valuable to monitor the health and maintain the configuration of the controller, arrays and individual drives, doing everyting live, without shutting down an OS and experiencing downtime.
A controller stores configuration both in its NVRAM and on drives. MegaRAID uses SNIA DDF on-disk metadata format, which many other vendors use too, so that RAID could be imported by various RAID controllers of different vendors and even by the Linux kernel software RAID MD driver, if you connect drives to HBA instead of RAID controller.
When you put the drive that contains DDF metadata into a controller and on-drive metadata doesn't correspond to the data in the controller NVRAM, it will mark drive as containing a foreign configuration. You can tell controller to adopt that drive, e.g. to copy its configuration into NVRAM, by importing a foreign drive.
The drive only contains the information about an array it is member of, not about other arrays of something else about the controller, so import should not have any impact on any other objects in the controller.
To be safe, make backups (isn't that obvious?), as always. It could be worth making an image of one of broken RAID1 members too.
Also, clearing the configuration shouldn't erase data. I once mistakenly deleted a running RAID10 (using megacli tool from an OS and mistyped the logical drive number), system failed into kernel panic, because the root file system was located on the deleted LD which disappeared. Later I re-created the array with former disks without initialization and the system booted from it as if nothing was happened. It's an initialization process is what actually zeroes a VD.
