Yes you can pour bleach down the toilet and bleach is a very good cleaning solution to disinfect and clean a toilet.
Pour some bleach down the toilet bowl and let the bleach sit in the toilet bowl for 10 to 15 minutes and then scrub the toilet with the bleach and water in the toilet bowl.
And then flush the toilet.
One thing to note that is very important to mention is that you should never mix bleach and ammonia or any toilet bowl cleaners together with the bleach since it can create a toxic and deadly gas.