No shampoo that I am aware of I'm afraid. Some of the new products like Bravecto might work, but I've no information as yet. One of the problems of harvest mights is the clustering on the paws, and the level of frontline from the spot on in that area was small - hence the need for the spray. Advocate - I don't know, I've never tried it and I'm not aware of it working.
OK, time on my hands so I've done a search. There isn't much published because Harvest mites are very localised and only around for August.
Vectra £D might be effective - one ingredient was used in a French study to fair effect.
Advocate was used in some cats, unknown effect,
Stronghold seemed to be effective at killing the mite within 2 days in cats (no reason not to work in dogs)
Bravecto has some effect against spider mites, which are closely related
However, check with your vet first!!
