if it`s only in certain pots and it`s Garlic you can smell, may I take a guess and say these are not Stainless steel pots :)
the reason I say this is that SS will eliminate garlic odours by breaking down the molecule responsible for the smell, other metals and pot/pan coating won`t do this, and since this smell particle is an oil when you have freshly washed it there`s still a coating of the smell under the layer of water, when this evaps 100% the smell comes back.
I could be wrong, but it would perfectly the info you`ve given us so far.
edit: Taken from my other Site:
active sulphur species in garlic and onions; the volatile selenides in
garlic, cabagge, and broccili; and also the chlorides in salty water will
all attack and destroy the passive film of most stainless steels more
quickly than the film can be repaired in a low oxygen environment.
Some of the smelly compounds will bind to your hands ( onto proteins,
lipids etc ) and will become non-volatile ( non-smelly ), but the number
of binding sites is limited, hence any excess of smellies results in
By binding to the metals in the stainless steel bar, the unbound smelly
compounds on the surface your hands are transformed into non-volatile
( and thus non-smelly) compounds and complexes on the surface of the
stainless. The new surface layer, which is weakly adhering and fragile,
will be continuously abraded off by the active rubbing of the bar and
replaced by oxides using oxygen from air or water."
this should give you an idea what`s going on :)
So long and Thanks for all the Fish ;)