I don't think they rot. I rember hearing that sailors used to do this to their oranges to preserve them.

Here's a quick link I found.

Here is a link that might be useful: Pomanders

There are lots of sites on the Internet with directions... here are a few hints/ideas:

Yes, you can use an apple, orange, lemon (and probably even a lime!).

You can put two bands of fairly narrow masking tape on the fruit first, vertical bands overlapping at the top and bottom of the fruit. Push in the cloves, leaving the taped bands unstudded. After all the cloves are inserted, remove the tape. After the fruits are dried, run ribbons in bands where the tape was, creating a hanging loop.

Be sure to use some instrument (nail, knitting needle, round toothpick, etc.) to punch the holes in the fruit before you try to put in the cloves or your fingers and thumbs will get VERY sore!

You can create designs with the cloves, inserting them in rows, swirling patterns, etc. (Plan your designs before you punch the holes with the nail or whatever you use.)

After the cloves are all inserted, wrap the fruit loosely in tissue paper and set aside to dry for approximately 3 to 4 weeks in a dark place. This is why you should get started on the project at least by Thanksgiving.

If you use an apple or fairly large orange, it will take a LOT of cloves. Be on the lookout now for bargains in whole cloves or you'll find that these little pomanders will cost you several dollars a piece to make!

I made lots of these back in the early 1950s using only oranges and apples and whole cloves. I did not use any orris root powder or other spices. And mine did just fine and lasted for years. Once they are dry, they don't deteriorate, they just loose their fragrance over time.

This is a old or older than Victorian days craft. I love them but was never successful in making them.