Yes. If rust forms inside the lugs it can make it difficult to fine tune a drum - all the rods should turn freely with no notchy-ness (is that an real word?), also if you decide to use something like a tension watch any rust inside the lugs or on the threads will give false readings.
Every time I change drum heads I dip all the tension rods into a shot glass filled with oil to cover the bottom 1" of the threads, place them into an empty cup to let the excess oil run off, when I reassemble the drum the oil on the tension rods also lubricates the lugs. About once a year I completely strip my drums to give them a good clean up, I also lubricate all the threads before re-assembly.
Apparently smearing a little Vaseline or white lithium grease on the threads of the tension rods is better than oil but I've never used it.
It's not necessary, but many people like to add a bit of their preferred lubricant.
I've never felt the need. The downside is that most attract dust and dirt. If a rod isn't turning smoothly, I just run a 12-24 tap through the receiver and a die over the t-rod threads. I very rarely have to do this.
Nothing wrong with adding a lubricant, though. Just not my preferred approach.
Hi Porky, if you do oil or grease your be sure the the tension rod is clean of debris and if not clean with a small soft wire brass brush or as stated a die. Remember the die needs to be just a little bigger than the threads because you don't want to take the chrome plating off the lug. Smaller tape size if you are doing the receiver.
Note: If you have Sonor kit and have the TuneSafe system use pure synthetic grease or oil because of the receiver of the TuneSafe system inside is made of a harden plastic. And petroleum base products will deteriorate the plastic over time. Same with any other type receiver lug that uses plastic internally to hold the tension rod.