For dual swap partitions I have been using the program Flopswap for a long time and just forgot about this issue.

Flopswap contains a script to swap from SD card /dev/mmcblk1p3 to /dev/mmcblk1p2 back and forth to prevent swap space fragmenation and that really helps.
You can remove the SD card safely after using the flopswap option: "swap to device"

51 days uptime and fast swapping.