Last year it wouldn't stop raining here and I had to pull my garlic from muddy soil. There was a wheelbarrow full of rainwater, so I swished the roots through it figuring they were already wet, so why not? I would normally never do this, but it got the mud off and the garlic cured and stored as well as it usually does. Good luck! I wouldn't leave it in the mud tho.

I agree with planatus. About the washoff part too; they are already wet anyway. Just take special care to provide ample air circulation during curing.

Thanks for the comments, that's a big relief. Fortunately I've got a good place to cure them once I get them up.