I've done that. I had a stupid 8-bit adventure time in my cart from a previous attempt when I was trying to figure out the order of the three buttons that don't always load with text. Did this in preparation for a big drop, so even if buttons didn't load, I'd know which ones they were. Then fast forward a few weeks for the next drop i wanted, get to checkout page, and have that stupid adventure time still in my cart, which I had to edit (during heavy server load), and still managed to get an order in. I think that was for the ED2 drop. Now I always login ahead of time and check my cart, if I remember too.