Problem with Drop Down and Checkbox fields

I've just installed Anton's Conditional Fields and it should alleviate this problem.  However, I still feel that there should be some way for the user to clear the field if that's what they want. 

I've just discovered this: 

If a member selects an item from a dropdown field or check box, it's locked in. If they decide they've made a mistake, they can't remove their choice, they can only choose another option.

I'm using a "worst case" scenario here. Let's say the Admin has added a field for Alcohol and he's offered the following choices: I drink socially and I drink a lot. The admin has assumed that if the person is a non drinker, they won't make a selection and the question won't appear in their profile.

I'm a non-drinker, but in my haste, or confusion I click I drink socially. After I've saved the edits, I can't go back and remove my choice. I have to leave it there or change it to I drink a lot.

I tried putting in a blank option, but that didn't work.

Any suggestions?