Unanswered Maintenance on unthreaded rods

I just discovered that I should be using lithium grease on the threaded rods, so I applied it today and now the squeak is gone. What product should I be using on the x-axis smooth rods and the y-axis smooth rods? Should I be cleaning them and applying some kind of lubricant?

 

Bearing manufactures recommend a grease with a NLGI 3 rating.
These bearing aren't a real precision bearing. They start at $30 and up.
The lithium you're using for the screws would be fine.
Pull out the rod and smear some inside the bearing. Push the rod back through and wipe off the excess.

 

I use this on the screw rods on my printers.
http://www.amazon.com/gp/product/B000XBH9HI/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

And on the regular straight rods I use a little bit of this...though the above works too.
http://www.amazon.com/Tri-Flow-TFBC...1432429114&sr=1-1&keywords=Tri-Flow+TFBC20027

 

Dry lubricants are probably ok, as I don't think in this application it would be considered "high speed".
But, per a bearing manufacturer: "In high speed applications with rolling elements, dry lubricants will cause the elements to skid which will increase wear and therefore, reduce life."
Just in case, I think I'll stick with a light grease on the linear rods.