Mud on White trousers- how to get it out?

[Jux]

DD has a brand new pair of white trousers. She was in the garden mucking about with a couple of friends, they were chucking a bit of very dry earth at each other. Some went in the pocket. As the trousers were getting a bit grubby I washed them.

I did my best to get all the earth out of the pocket first, but obviously didn't entirely succeed, as when they came out of the machine there were a couple of splodges of dirt left in the seam. They really show badly and look awful.

I'm soaking them in diluted bleach, but it doesn't seem to be having much effect. What else can I do?

TIA

rub some washing up liquid into the stains and rewash

Tried Ariel excel gel? Seems to get most stains out.

I use vanish spray - spray on inside AND outside of stain, then in 40 degree wash with powder detergent (Lidl) and vanish white
Gets cricket whites white every time!

Thanks all. I've not come across Ariel excel gel, but I don't study the washing detergent aisle!

DH turned the pocket inside out, scrubbed away at the seams with a toothbrush and some Persil, and eventually I washed them again,using Vanish spray which I'd forgotten I'd got. Almost perfect and what's left can be put down to shadow.