Generate clean url slug in C#

slugify.cs

public string Slugify(string s)
{
    if (string.IsNullOrWhiteSpace(s)) return "";

    // removing extra spaces and keeping just one
    s = string.Join(" ", Regex.Split(s, @"\s+")).ToLower();

    var specialPhases = new Dictionary<string, string>
    {
        {"c#","c-sharp"},
        {"f#","f-sharp"},
        {"_","-"},
    };

    foreach (var item in specialPhases) s = s.Replace(item.Key, item.Value);

    var matches = Regex.Matches(s, "[\\w]+");
    var words = new List<string>();
    foreach (Match m in matches) words.Add(m.Value);

    return string.Join("-", words);
}

// Usage
var slug = Slugify("I love C# ~!@#$%^&*()_+=-|\\/';:}{[]"); // i-love-c-sharp