So I was having this issue too and the way I fixed it was that every time I received silver ash I infused it into my other characters armor and then when I would run bonfire again I wouldn't receive 100 for 20 leaves but it would give me just enough to level up the armor and it took a little bit of time but it was better getting 50 ash than 1 at a time for 20 leaves. I hope this helps :)