That’ll take care of most of it, but from the article:

HPV tends to be resistant to hand sanitisers and requires a concentration of 10% bleach to destroy that tough, protective protein shell

That said, alcohol dries very quickly, so if you hit the seat with that, let it dry, then build that TP bird’s nest, you’ll have probably as good of protection as you can get without carrying bleach or whipping out an impervious barrier of some kind.