I normally suggest a person place the wire & gravel etc on 3 sides of a shed most often used first. then, on the 4th side,, the one most exposed & least attractive to the critter,, I say to add the wire & gravel to all but one small area about 6"-12" wide. It gives the critters a way to exit,, and makes it harder for them to re-enter.
To assure all critters are out prior to closing up the one small spot,, you have a few options.
(1) Add a game camera to see if there is any activity of INCOMING critters.
(2) To the entire area except the one small opening,, add temporary vision blocking stuff. Such as black plastic, firewood, rocks etc to where the only "daylight" opening is the one spot where the critter can easily see to get out. This way, they have a safe way out,, AND if it's in a spot they don't feel safe in movement,, they don't want to return there.
(3) You can add an overlapping section of wire on the outside,, using rabbit cage clips to where they have a "door" to push against from the inside. By adding it to the outside & the door being wider & a little taller they can get out,, but if they try to get back in,, it can't be pushed inward. This,, combined with the temporary daylight blocker funnels them to that spot.
Not many chemicals or smells are truly very effective against the many potential critters that roam our homes & woods. Peppermint oils have been somewhat successful on some critters,, but not others. The same goes for citrus types of oils.
One thing a lot of people have used with reasonable success as a repellent against SOME critters is a wood treatment product designed for carpenter bees & wood insects. It's main purpose is to stop carpenter bees & other insects against boring holes into wood. But it has a citrus smell that has a little success in being a rodent deterrent. It's sold locally by a company called; logfinish.com and the name is "NBS-30." It can be mixed with water or stains and applied.
While I was typing this,, MHtractorguy mentioned live trap & honey buns. For skunks, raccoons, opossums, rats, that's effective. But since he's in NC I want to mention;
"In NC,, ANY trapping of wildlife requires either a trapping license or a Depredation permit. Even if on your own property & for animals causing problems. A NC Depredation Permit is free,, but the issuing agent must verify damage prior to issuing one. And all trapping laws must be followed. Traps properly marked with the owners name & address. Traps checked daily and any live captures must be handled according to State law. No relocation of any potential rabies vector species is allowed."
If in another state,, I STRONGLY suggest you contact your local wildlife agency prior to any trapping of any wildlife,, even if the animal(s) are causing you problems. Know the laws before you break them.