Need help with defining white sludge

[wahenee]

I was trying to recover some gold from what use to be the lining of a hair growth helmet. The helmet uses LED lights and the insert of the helmet is plastic with little squares of gold plating. I cut the inserts into small pieces that only shows the gold. I used the vinegar & hydrogen peroxide method with salt. After about two weeks it left me with this white sludge on the bottom not too many flakes. What should i do. Or even better what process should I have used?

 

[anarxi]

make aqua regia, and throw these pieces in there, heat it, dissolve the gold
(it's on the surface)
then pour the acid into another glass.
Fill the plastic waste with baking soda solution and throw it away