On Fri, 24 Aug 2007 20:08:33 -0500, Karl Townsend wrote:

Since H2So4 does a nice job - I use professional plummer drain cleaner -
strong solution of H2So4.

I'm not a chemist, but I'm pretty sure most drain cleaners are strong
caustics, not acids

There are both lye based as well as sulphuric acid based cleaners.
Your Ace Hardware probably has a bottle of concentrated, 80%, sulfuric
acid, sold as drain cleaner, that you can buy and use as drain
cleaner. It is very serious stuff and works very well. Dissolves human
hair, etc. Such a bottle lives on a shelf in my garage and I can
attest to its efficacy. It converts at least a part of the scum from
drains, into stinky H2S.

i