I encountered a mild case with some miniatures and hunted around the internet for solutions.
First remove any detritus. I used a cheap wire brush for car repairs with brass, steel and nylon bristles in the pack.
Wear gloves and a face mask. Lead is toxic. Dispose of any bits carefully.
After lots of searches, I opted for the pure gum turpentine and pure mineral oil mix soak. Not long in the mix, leave to dry.
Turpentine acts as a solvent on white lead.
A lot of the "cures" are nonsensical; one suggests treatment with an acid - as it's caused by an acid I'm not sure how this helps!
The turpentine solution gradually accumulated a gritty layer of lead sediment. No problems since although they do discolour.
https://iron-mitten.blogspot.com/2023/10/preventing-lead-rot.htmlNeil