Why? When you could use your oven or a toaster oven? What else does it do?
I am so against one use equipment!
Linda C

I don't have a toaster oven and heating the entire oven for so long, just for garlic is a waste of energy.

Cook the garlic when you are cooking something else...3 heads of roasted garlic is a lot for one meal....and I suspect the energy use would be considerable for just roasting a little garlic.
Do it when you are roasting meat of veggies and save it for another day....unless you have unlimited storage and can afford an appliance that will be used perhaps twice a month?? Or less often???
You can also roast garlic on a heavy dutch oven on top of the stove.....and you can use the Dutch oven for soups and stews.
Linda c

Hey, I've seen one of those too and ran away from it. I agree with Linda.