Thats a really good idea
I didn't think of that, so surely there is something (soaking in Oil) that would help the sparks? we just have to find out what haha
Its not quite as straightforward as that....
If the donor cloth was soaked in oil, that oil would be cooked out during the charring process - reducing the oil to a thick sticky gunk (if any is left at all) which can stop the fabric fluffing up.
If there is an oil residue left on the cloth, it can help if the charring is not totally complete - then when you try to repeat the process, the second batch doesn't work as well - despite following the process to the letter.
ATB
Ogri the trog