Fuel tank access plates-catching filings

Slow leak has developed in one tank on my 4 yr old RV-8-a. I built the original tanks and the leak is new.
Going to pull the tank, track down leak and repair with pro seal.

Following conventional wisdom, I?ll be installing access plates as necessary.
Looking for suggestions for
Removing filings resulting from cutting of access plate holes and drilling rivet points.

I was thinking I could catch filings from drilling rivets holes by putting Vaseline or equivalent on inside of access hole ( remove later with acetone and rag).

Still not sure about best way to remove filings from cut of access holes.

Any suggestions ?

I recently had to repair a tank.
1. I put the tank on the sawhorses and had the baffle facing down. I then laid on the ground and drilled up so as much junk would drop straight down.
2. I used a rag to clean out anything else - the metal shavings got caught in the rag
3. I swished some fuel around and drained.

Hub caps

If Vans still sells the RV3 hub caps, there was a post a while back about using these instead of the flat close out plates. They are dished and will give a little more capacity to the tank.