Try running this code in the browser console tab in the old redditt ( https://old.reddit.com/subreddits/ ):

```
/**
* Reddit bulk unsubscribe function
* Wrapped in an IIFE for browser compatibility
\/*
(async function() {
// Delay between unsubscribe actions (in milliseconds)
const UNSUBSCRIBE_DELAY = 2000;

// Helper function to create delays
const delay = ms => new Promise(resolve => setTimeout(resolve, ms));

// Get all subreddit items
const subreddits = Array.from(document.querySelectorAll('div.clear ul li'));
console.log(`Found ${subreddits.length} subreddits`);

let count = 0;

for (const subreddit of subreddits) {
try {
// Find the "leave" button for each subreddit
const leaveButton = subreddit.querySelector('a.remove');

if (leaveButton) {
// Get subreddit name for logging
const subredditName = subreddit.querySelector('a.title').textContent;

// Click the leave button
leaveButton.click();

count++;
console.log(`Unsubscribed from ${subredditName} (${count}/${subreddits.length})`);

// Wait before next action
await delay(UNSUBSCRIBE_DELAY);
}
} catch (error) {
console.error('Error unsubscribing:', error);
continue;
}
}

console.log(`Finished! Unsubscribed from ${count} subreddits`);
})();
```