They picture an unsealed bearing. If that is what you have then I would suggest some lube. Of course when you do that the lube is like a magnet for dirt. So you will have to clean them after each bash session. Or at least you should to prevent premature ware.
you do not want to put too much lube on the clutch bearings as it can make its way onto the bell and shoes..and then you would have a slipping clutch. i say just spend the 8-10$ and get new bearings...they should last a very long time anyway.
Trinity sells bearing specific lube. They've got general ball bearing lube, and then they sell "Royal Drops" which are their high performance ball bearing lube. I use the Royal Drops on all of my bearings and they work great.