Thank you for your response, Rob!  Actually the MAIN reason that I used
Vaseline to get poor Scooter out of the harness was just how very panicky he
got, and then I got, as we discovered that the buckle was locked shut around
him.  I was in the bathroom at the time, so I simply grabbed the Vaseline,
gooped him up under the harness, threw in some soap and water on top of it,
and slid him right out.  I just thank heavens that the buckle didn't lock
tight as I was sizing it on him the first time around (and found that I had
made it a bit too tight!)
 
I'm sure that I could have wriggled him out if I tried (I do leave at least
a finger's worth of space in each strap for him), but I was too afraid that
in his squirmy, scared state I would injure him in the process.  It was far
less traumatic to slide him out all at once (he's one of those ferrets that
doesn't mind water much as long as he's not immersed).
 
Your point about cutting out the center tab was an excellent one, as long
as it doesn't affect the proper hold of the buckle in the process.  For
myself ... I would never use a Hagen harness again, simply because it was
such a bad experience for both me and Scooter.  Others need to make their
own decisions.  Thanks again for the note!
 
- Ela
[Posted in FML issue 1635]