I find this 7 strand plarn rope great: I tried it and it is very easy braiding and really strong.
I also tried it with yarn from my stash and the cord looked also good.
There’s no photo because I find the colour combination dreadful – it’s just been a quick try ;-))
And if you don’t need plarn cord, look for other ‘uses’ of plarn ;-)
Links:
7 Strand Plarn Rope (Useful & Durable 7 Strand Rope (cord) from Plastic Shopping Bags)
Here at unikatissima:
Entries containing the word ‘plarn’