Search and Replace in ODT using AODL

Recently I needed to create a way to search and replace a word in a OpenOffice OpenDocument ODT. It would seem the project itself already has a library AODL (take care, at least two other project pages but with older code) that exposes the format model but I didn't find any utility methods like search and replace functionality. I've created two versions of the method, one a old-style, imperative approach, and the other, a LINQ version. As I'm still new to LINQ it would seem that the classical approach produces a more efficient code. Anyone care to chip in and make a faster algorithm? In this particular version I'm just going for simple string equality, I didn't want to go with other StringComparison methods (just look at the Equals overload method).

 public static void SearchAndReplaceString(TextDocument document, string searchText, string replaceText)
        {
            var content = document.Content;
            
            foreach (var item in content)
            {
                if (item is Paragraph)
                {
                    foreach (var textContent in ((Paragraph)item).TextContent)
                    {
                        if (textContent.Text == searchText)
                        {
                            textContent.Text = replaceText;
                        }
                    }
                }
            }
        }

 public static void SearchAndReplaceStringLINQ(TextDocument document, string searchText, string replaceText)
        {
            var content = document.Content;

            IEnumerable<Paragraph> paragraphs =
                from item in content
                where item is Paragraph
                select (Paragraph)item;


            foreach (var paragraph in paragraphs)
            {
                var paragraphText = paragraph.TextContent.Where<IText>(t => t.Text == searchText);
                foreach (var textItem in paragraphText)
                {
                    textItem.Text = replaceText;
                }
            }
        }

I should point out this method matches only single words.

Fix 1. Replace text if under table structure, doesn't work if the Cell is in the header.

public static void SearchAndReplaceString(TextDocument document, string searchText, string replaceText)
        {
            var content = document.Content;
            ReplaceInContent(searchText, replaceText, content);
        }

        private static void ReplaceInContent(string searchText, string replaceText, ContentCollection content)
        {
            foreach (var item in content)
            {
                if (item is Paragraph)
                {
                    foreach (var textContent in ((Paragraph)item).TextContent)
                    {
                        if (textContent.Text == searchText)
                        {
                            textContent.Text = replaceText;
                        }
                    }
                }
                else if (item is Table)
                {
                    foreach (var row in ((Table)item).Rows)
                    {
                        foreach (var cell in row.Cells)
                        {
                            var cellContent = cell.Content;
                            ReplaceInContent(searchText, replaceText, cellContent);
                        }
                    }
                }
            }
        }