microSD card: wiping before selling

♠ Problem statement : I want to sell a 32 GB microSD card, previously used to boot a Raspberry Pi. % diskutil list disk4 /dev/disk4 (external, physical): #: TYPE NAME SIZE IDENTIFIER 0: FDisk_partition_scheme *32.0 GB disk4 1: Windows_FAT_32 BOOT 268.4 MB disk4s1 2: Linux 31.7 GB disk4s2 For that, I would like to securely wipe it. dd is my preferred tool to do so. % diskutil unmountDisk /dev/disk4…