[Karen Hart]

Of course, stripping off oils and unclogging pores would be advantageous when applying any product that you want to be fully absorbed.
That would apply to the entire breast, or any other patch of skin, as well as the nipple.
You don't have to use alcohol though. I think a shower would suffice, if that's convenient.

You could also use a remover that is not quite so aggressive as straight alcohol, maybe like witch hazel or a facial toner or just soap and water.
Sure, you should definitely re-apply some type of oil, lotion or moisturizer afterward to restore the balance.

Karen