I did all three steps. It has been several hours and the phpinfo still shows 5.2.17. I opened the .htaccess to verify the code was there. It is.
# CUSTOM CODE TOP PHP/PHP.INI HANDLER/CACHE CODE
# Use PHP 5.3
AddType application/x-httpd-php53 .php
So I dug around a little more. HostGator has my site in this directory: /public_html. I found a generic .htaccess file in the directory above that in “/”. I renamed that to .htaccess-old. It works now!
Thanks for your help!