On Tue, 3 Jan 2006 00:36:45 +0000, The Natural Philosopher
wrote:

Although it is sold commercially as a drain cleaner, never use caustic
soda to open a drain. It will combine with the grease from soap or food
wastes to form an insoluble compound.

That does not compute. I've used it many any times to dissolve fats - on
cookers and in the drains.

It's generally a bad idea to use chemicals on a _totally_ blocked drain.
If it's _that_ bad, then there's something physical down there and
you're just going to have to use physical methods to shift it.

One of the most effective toilet blockers known to man is toilet roll
and a bar of soap. They're both perfectly soluble (sic) in small
quantities, but put a whole bar down there and it just ain't going to
wash away. "Soluble" only works in a sufficiency of solvent to do it -
a grease blob in a narrow pipe is perfectly capable of resisting
dissolution if there's no flow, no matter how much caustic soda you get
to it.