I'm gona get flamed but I think its all parrot shit Im hearing.

Is there some interaction between Dbol and Test that helps keep the DBol gains?????

Its simple.
People who do Dbol only cycles mostly wont know much about AAS(or diet) so they may have a harder time maintaining gains than an experienced user.

The big point is......
if you put on 20lbs with a Dbol only cycle then roughly half is water and your going to lose that.
Sure why the fvck would you want to keep water gain anyway!!!
Sounds so stupid when people say "good luck keeping ALL your gains"

Some might be disappointed when they drop the water size and that ads to the myth IMO

At the end of the day you will still have made great muscle gains!!!!!!