The obvious question is what are the failures? While it may not matter to BB in this case, a drive going read-only is far less of an issue than losing data.

For what it's worth the only SSD I've had that failed into a readonly state was (IIRC) an Intel one. Had others fail in worse ways (and some Pacer drives that just silently corrupted your data - proved this out with a test program I wrote that filled the disk with pseudorandom bits and read them back).

I always do this with new USB sticks. Write one random file, fill the drive with copies and then test for the checksum, for example for a 16 gig thumbdrive:

    $ cd /path/to/thumbdrive
    $ dd if=/dev/urandom of=test.bin bs=1000000 count=100
    $ for i in $(seq 1 160); do echo "Writing file $i"; cp test.bin test$i.bin; done
    $ md5 test.bin
    MD5 (test.bin) = 0d3c4fe338109b09b61fcea3e11b0e4b 
    $ ls *.bin | xargs md5 | grep -v 0d3c4fe338109b09b61fcea3e11b0e4b

I think it does practically the same thing as your method.