It's not only a great idea but rather I will see it as major preparation to take profitable trade so the use of demo account is important when it's come to forex at least you need to spend 6months in your demo platformUsing a demo account to learn forex trading is a great idea no doubt about it. But i believe it would be better to gain more knowledge picking up classes or getting someone to put you through, after that you can use your demo account to put all that you have learnt into practice.