This nis a tried and true method.
You need two dropper bottles. The first has water with a couple of drops of detergent. The second has 25% white glue 75% water.
Get the dirt in the right spot, drip on the detergent all over the dirt. This will break the surface tension for the next step.
Drip the white glue solution all over the dirt. It will look awful, at first but will dry and everything will be glued in place and look matte.
Good luck.