Ryan,

Don't be too concerned with the soap scent. One of the best and most widely used egg cures is Borax which is a soap itself. Whatever soap residue/scent that is left in the jar should not make much difference and might even help catch fish. If you are still worried about it, then coat the inside of the jar with a thin layer of shrimp, anise, or sardine oil.

Justin
CEO, Sauk River Steelhead Ranch