bob wrote:
Years ago I bought a bottle of sulfuric acid from a hardware store with
the intend to open a clogged pipe. I ended up opening the clog with
another method. The bottle sits unused.

Many toilet bowl cleaners use hydrochloric acid as a main ingredient,
since sulfuric acid is similar stuff, can I use it as a toilet bowl
cleaner?

Why not. I use bleach, sometimes Scrub Free. An acid or base will clean
well.

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All is as it is.