I have read many of the pre-existing "stinky garbage disposal" threads
out there, all of which relate to odors caused by organic agents or
rotten food, but I have a new one. The previous owner of my house
apparently liked to dispose of his old ashes (cigarette, cigar,
pipe.... I do not know) in the garbage disposal. The upshot is that
whenever I run it there is a horrible smell of stale cigarettes that
comes from the unit. I am sort of lucky in that the smell comes form
the unit itself -- under the sink -- and not from the actual ingress to
the disposer. So if I do not open the doors of the cabinet under the
sink, then the smell is not too bad.

Still I would like to remedy this. I have tried all the old stand-bys:
- ice cubes
- backing soda followed by vinegar
- boiling water (although at least one poster said not to)
- bleach
- lemons

I have also manually cleaned all the accessible areas of the
drain/ingress (i.e. stick my hands in and scrub).

I suspect the problem is caked ashes somewhere in the unit.

An obvious solution seems to actually take the unit off and then
attempt to clean it. However I found that locking ring would not budge
(perhaps the subject of a future post). So I am looking for ideas that
do not involve taking the disposer apart.

Thanks