I like a 3-in-1 (sewing machine) type of oil. Just a few drops and you're golden. But I will defer to the experts.

I put a dab of vasoline into the insert before threading the rod in...The rod gets an even coat this way...Normally when I do a deep cleaning/tear down of the drum, I will clean out any excess dirty vasoline because that collects...

Cheers

3-in-1 the way to go. If it works for Granny's sewing maching it'll work on tension rods

I use Super Lube oil. It's a synthetic Teflon-bearing lube that will never dry out or solidify. Pricier than traditional lubes, but so much better.

Sounds good. One question: does it collect dirt?

Tri-Flow similiar to what JrFrond described. Teflon based lube

Tri-Flow isn't too bad about collecting dirt, at least from my experiences with using it on bicycles.

I'm also using Tri-Flow. Used it for years with no problems. A little goes a long way!

White lithium grease from the tube. Available from the Depot or any auto parts store.

$3.00 worth will last years. Easy to apply from the tube..."a little dab will do ya".

Cheers!

-kellyj