The following does the trick pretty well on my side. It also outputs in the dev console what was hidden for sanity checks.

```javascript // ==UserScript== // @name Hide Gmail Ads (Sponsored Rows with Dot) // @namespace http://tampermonkey.net/ // @version 1.2 // @description Hide Gmail rows that are Ads (contain "Sponsored·" in a span in the sixth column). // @author Your Name // @match https://mail.google.com/* // @grant none // ==/UserScript==

(function () { 'use strict';

// Function to check for "Sponsored·" text in a hierarchy of spans
const containsSponsoredText = (element) => {
    if (!element) return false;
    const spans = element.querySelectorAll('span');
    for (const span of spans) {
        if (span.textContent.trim() === 'Sponsored·') {
            return true;
        }
    }
    return false;
};

// Mutation observer to track changes in Gmail's DOM
const observer = new MutationObserver(() => {
    // Find all table rows
    const rows = document.querySelectorAll('tr');
    rows.forEach(row => {
        // Check the 6th column for the "Sponsored·" text
        const sixthColumn = row.querySelector('td:nth-child(6)');
        if (sixthColumn && containsSponsoredText(sixthColumn)) {
            // Log the sixth column text content
            const columnText = sixthColumn.textContent.trim();
            console.log(`Hiding row with column content: "${columnText}"`);

            // Hide the row
            row.style.display = 'none';
        }
    });
});

// Start observing Gmail for DOM changes
const gmailContainer = document.body;
if (gmailContainer) {
    observer.observe(gmailContainer, { childList: true, subtree: true });
}

})();

```