quiltsfor

This may be a weird/dumb question, but I've been tossing it around all day today.

I bought quite a few packages of replacement rotary blades when there was a craft store having a sell out. They are Olfa blades, in the yellow plastic cases. However, it was a few years ago and I'm still using them up. But, today I came upon my first issue and I'm not quite sure how to proceed.

When I opened a plastic holder that contained multiple blades, I'm finding the the oil sheen that is usually on them is dried up and the blades are tacky/sticky to touch. I've wiped them off with alcohol (once I get them unstuck and apart) and it cleans the old sticky dried oil right off.

Normally when I change a blade, it has oil on it. I just put it in the rotary cutter and then wipe off the exposed part of the blade to keep the oil off of my fabric. But, these old ones are just sticky and gummy.

So, I guess my questions would be, can the blades be completely free of the oil?
As in should I have been wiping them completely off to begin with when I insert a new blade?
Or, if I find a blade like above, should I be putting a little bit of light oil just around the center hole or not?
And, if I have remaining blades in the plastic case, should I put a little oil on them before I put them back for later use, or just put them wiped clean back into the case for later use?