I have read all the threads I can find here on this. I have a mulberry bag in thick hide that has been stored for a while. I decided to get it out and it had a slight fusty smell on the leather. I then spent hours reading everything on here about this. So I thought I would try the soda first. I got a large plastic container and put a layer of soda on the bottom with a couple of paper towels over then the bag. Put on the lid and left for 24 hrs. When I took it out it smelled worse. I assume the soda has drawn the smell to the surface. I then realised I had used soda crystals instead of baking powder. The soda crystals are powder. Firstly I have made a big boo-boo here? The powder coming out of the tub smells extremely fusty. Shall I try again with baking soda? How much do you use and how long do you leave before changing the powder? If it takes a while it could be a costly remedy lol. Any advice gratefully received! Thanks