everyone has heard that before
most have ripped that tag off the cord long ago
-whether or not they should have isn't the point

I think the problem with that statement is that a 4 stop overexposure is not ideal, either ..and that is the reason for finding a developer+ which might possibly help
i think most would agree that certain developers and certain ways of developing lose you speed while others give "full" speed
It's pretty clear if you've overexposed and you're worried about it
use a lower film speed developer etc and perhaps there is no reason to worry
lemonaid from lemons
obviously if his original film speed stems from a speed loss developer then another film speed loss developer won't do anything for him

If you make potato salad and the salad isn't tasting right what do you do?
just hope a day in the fridge will make it better
just eat it anyway
eat less? lol
or experiment
you may make it worse
you may remedy it
if you already consider it "ruined" or "not good enough"
what's to stop you?

this guy should develop a snip of film- or another roll shot the same
test it out
if not to liking

he is experimenting by doing whatever he's doing in this thread
but it falls short of true remedy
and he's already "in the unknown"

I'm suite sure you can lower film speed by 2 stops rather easily especially if your normal developer is a normal developer

how about let it sit around for a few years? That might have lost it a stop in speed.
develop it when your're 55
probably right on!