I don't clean onion or garlic. I pull it out of the ground and let it cure outside. Most of the dirt comes off this way, but not all. Good enough for me. I don't cure it only to remove the dry layers of skin.

We don't clean planting stock but anything I am going to use in the kitchen I would at least clean a little. I clean by taking off one paper layer. We cut our roots at harvest so they are already pretty clean.

I actually wash mine. Started a couple years back, when it was so wet the only way I could get the claysoil off them was to swish them around in a bucket of water. I then laid them out on a board, out of direct sunlight, until they were surface dry. Then I bunched and hung them as usual.

Suffered zero losses that way, and have done it like that ever since.

And I've wondered, too, why we are told not to wash alliums?

I pulled mine this year when the dirt was still damp and so had large clumps of dirt. I waited two weeks, then was able to knock it off with the roots, and in the process of trimming the stems, usually a layer of skin, which around here almost always is black with mold, comes off. I then hang them in orange sacks in the storage shed, and they keep just fine.

Although I had the best of intentions, giving storage a premium over appearance, I failed miserably. I cleaned a few bulbs, and then I couldn't help myself; I ended up cleaning all 200+. They were just too pretty, by and large, to leave them sullied.

More than half are going back into my garden in a month, so storage is overrated (or so I keep telling myself). Some are down to a single wrapper, but excepting a dozen or so who were left in the ground too long, they look great.

I used to laboriously brush the soil off the garlic. Took way too long. Following my husband's lwad, I simply spray them off with a hose as soon as they are out of the ground (they are damp from the soil anyway). I bundle, label and tie up, hang in the barn for at least a month before going to the cellar. Those for gifts have alonger stalk left on them. Those for my own use are clipped short.
I like to give garlic as gifts, they kinda have to look nice. I wouldn't want to hand someone a fist full of dirt as a gift ;-)
Maryanne in WMass

I harvest my garlic when they start to get dry leaves, on the day when only six leaves are green. Then I quickly wash the roots clean and tear of one leaf. That leaves you with a perfectly clean garlic, no mold or dirt. After curing i cut the roots and stalk. This way your garlic have five good layers of wrappers.