It seemed I was exposed to the beginner's luck curse, as the next few attempts ended in failure, with only one sword ending up being a white grade. I tried to take a break and revise my steps again, but Nada helped me out of my dilemma when she said:
"Your failure came from the cleansing process, you need to raise the total percentage of your cleansing to have better results."
I had to agree with her, as I did everything else right, and I couldn't spot any mistakes. I sighed, as this was something I couldn't fix on my own right now, so I only accepted that very low success rate.
By these failures, my stock of my liquefied mix was depleted, so I consumed some time making another one, then I started making swords again. this time, I didn't wait for the sword to cool, as I asked Nada for other molds, and she gladly gave me another two.