The way I look at this is:
Cheapo SS may be one of the definitive statements.
-SS is not always corrosion proof. Corrosion resistant would seem to be a better term.
There are different "grades/types" of SS...each with their own degree of corrosion resistance.
-The SS-grades having carbon added as a hardener (and are magnetic, to a degree)
and are more susceptible to corrosion.
Also:
If the SS cladding of the ramekins has been compromised (such as: scratches),
that will definitely allow an opportunity for corrosion to take place.
-
One other factor are the shampoos themselves.
The salts'-level/concentration of one may be higher than another.
Salts can cause shampoos to
"foam up like a dream".
Salts can also be a cause of corrosion.
The SS-qualities of the ramekins can be a determinate of its ability
to resist corrosion from substances...such as 'salts'.
Thoroughly, and completely rinseing all shampoo residues
away from all vehicle surfaces can not be stressed enough...IMHO!!
One more corrosion-factor:
Rainy weather/humidity: Speeds-up any corrosion process.
And:
Not to be an unthankful dinner guest at your home...
But I believe I would have to pass on the crème brûlée.
Bob