Using TEMP ON COMMIT DROP, but need logging too.

I've written a function that uses several temporary tables with the ON
COMMIT DROP option. This function does no updates to the database. Now I
would like to put in some logging. In otherwords:

insert into my_logging_table values (...);
commit;

Obviously I can't do the commit without dropping my temp tables.

What is a good way to implement my intended functionality?

Thanks, Mike