I don't know why I see this suggested for leveling. It's almost as bad as bataquiche.
Assuming that some recipes simply don't provide skill gain like others, I would suggest experimenting with other recipes, especially those that'll sell for a profit to cover expensive breaks. This npcs for 199g and costs about 400g to make with fire crystals at 900g/stack. I made a few attempts with 2 stacks of materials each over different moon phases and days. I averaged .3 skill per stack, the latest with only .2 skill gain per stack. That's 14400g in loss to make a little over a level. Bearing that in mind, spending a bit on cockatrice meat, wild onions, or wasabi for a fraction of the loss if any doesn't seem all that bad.