It has been mentioned in the posts that the SYN acquires an odour.
This has happened with my SYN. Today (after my normal wash with hand wash detergent) I rubbed an antiseptic tea tree lotion onto my SYN and let it remain for a couple of hours. I washed it off with several applications of hand wash detergent. It now has a slight odour of old tee trees. The other odour has gone - until next use?
(Odour = Odor = smell)
Hi. After use I put mine in a small plastic tub with a little washing-up liquid and pour some boiling water from the kettle into the tub. Leave it for 30 minutes or so and it should be nice and fresh.
You could also try a 10% bleach to water solution. Let soak for twenty minutes in it. This actually sterilizes the Aneros. But also removes any lingering smell in the process.
http://en.wikipedia.org/wiki/Sterilization_%28microbiology%29#Bleach
For some reason, the link above is not auto completing correctly. The section that is not red "(microbiology)#Bleach" is part of the link. So you'll have to highlight the whole link and use the copy and paste functions.