Then you wait one second after pressing j (until the timeout is over) and press k.
To be quite honest, that sounds terrible.
I don't think it's bad at all. I very rarely have to write 'jk', and using that combination saves me from having to either reach the escape key or having to use c-[. If the price I have to pay is waiting 0.5s (which is what I have the timeout configured to) once in a while, then I consider this a great tradeoff.
Caps Lock is one key, easier to type, and even more rarely used, though. I highly recommend it. =)
That's what I use too :). I also highly recommend it. I would strongly recommend binding either escape or ctrl to caps lock on every keyboard.