Washing lemons

Purchased unwaxed lemons to make my Christmas cakes and always use Delia's recipe but pack label shows wash before using as treated with Imazalil so do I simply run them under cold running water and dry with towel or should I drop them into warm water. Most fresh fruits show they need to be washed but no information is given as to how this is to be achieved.
What can I do with the lemons after removing outer peel because
I will have lots and pity can't be used for something.