gw remembers every url you specify on the command line or url list file
in the options table. -wipetodo has no effect on that. there's generally
no problem with that as those urls are already in the database and
won't get fetched again unless it wasn't able to fetch them the first time.
You can delete them from the options table with:
gw -st "delete from options where Name='URL' and String='http://yoururlhere'"
Or you can delete all urls from the options table with
gw -st "delete from options where Name='URL'"
That will prevent -rewalk from working. If you don't want gw to ever
remember urls, use the -O option, which will also prevent -rewalk from working.