Test one chip of each denom. If it visibly does not make a big difference then I would not bother oiling.
If you are going to oil what to do is get a drop or two on your fingertips, pick up the chip and massage gently, avoid the inlay so that oil does not get underneath. Drop on a big fluffy towel. When you have done 10-20, stop and dry them off with the towel. That leaves enough time for the oil to soak a bit into the chip.
You may want to just do a quick wipe of the rolling edge. Put a few drops on a towel or cloth and pick up a stack of 20 out of a rack and wipe it down the entire barrel and then put back.
As long as you dry the chips off with a towel then they should be good to go almost immediately. If the chips are wet then they will just accumulate dirt faster.
Most of my PCA's I did not oil and if I did, I just wiped the rolling edge.
These chips are all oiled
Except for the two on the left these are my secondary chips oiled above/unoiled below and you can see it didn't make a huge difference so I just wiped the rolling edges on the $5, $25 and $100. It was staining the $1 chips so I stopped oiling the rolling edges after a rack or so. When I ordered a bunch more from the Black Friday sale, I didn't bother to oil them at all because they pick up oil naturally anyways from use.
Here you can spot the oiled chip in the rack.
Rolling edges oiled only (except the $500s and the $1s, which I stopped oiling)