In a gist on GitHub Adam Wathan shares some macros that can be used to clean up a request.

Allows you to trim things, lowercase things, whatever you want. Pass a callable or array of callables that each expect a single argument:
Request::macro('filter', function ($key, $filters) {
    return collect($filters)->reduce(function ($filtered, $filter) {
        return $filter($filtered);
    }, $this->input($key));

If you want to hear Adam talk some more about troubles with requests (generated by webforms) and possible solutions, listen to this episode of the Full Stack Radio Podcast.