That site did work for me going to Blood Red. One thing I don't think it mentions, is that it appears to work much better if you feed the Chocobo with alternate items. So instead of feeding 12 × Mamook Pears, then 17 × Xelphatol Apples and then 19 × O'Ghomoro Berries for example. Do 1 of each until you hit the required amount.