I completed Standard with an S rank to unlock the infinite Samurai Edge before I took on Hardcore, so at least I didn't have to worry about ammo for zombies and could save the more powerful weapons for lickers, etc. If ammo is your problem, I suggest you do the same, because any weapon you unlock will retroactively be put in your item box, even in saves you made before unlocking them.
If that's not the problem, then... just walk past them? (And by that I mean, walk normally, because unlike what some guides will tell you, you don't actually have to move at a snail's pace to avoid them hearing you.) Lickers are very nasty female dogs!