Get white background on product photos?

For what it’s worth, here’s my attempt. It essentially takes the same approach as Scott’s answer, so credit should go to him, but with a different approach to the top roll-off.

I noticed there was a slight green colour cast which I removed in a pretty quick and dirty way too (though not very well).

The reason this has been so easy to do is that you have otherwise done everything right – it’s photographed with a light backlit background (normally you don’t want, but in this case you do) so it can easily be isolated just with curves.