If you want to remove ONLY <p> tags, try performing a regular regular expression replacement:
{$entry.entry|regex_replace:"/(<p>|<p [^>]*>|<\\/p>)/":""}
This will replace the <p> , </p> lines and all <p many attributes> lines with an empty line.
Let me know if that works. I tested the regex in PHP, not directly in Smarty.
source share