Removes all Amazon saved for later items on the cart page. It will only remove visible items. You might want to scroll first to make more items visible. To use paste code in developer console (Ctrl+Shift+J or Cmd+Opt+J in Chrome) then press enter.

deleteAmazonSavedItems.js

function deleteSavedItems() {
	var query = document.querySelectorAll("#sc-saved-cart input[value=Delete]")
	if (query.length) {
		query[0].click();
	}
	if (query.length > 1) {
		setTimeout(deleteSavedItems,100);
	}
	else {
		console.log('Finished');
	}
}
deleteSavedItems();

None of the above worked for me unfortunately, but after some iteration, I was able to get it to work for me:

async function deleteAllSavedItems() {
  while (true) {
    const deleteButtons = document.querySelectorAll('input[data-action="delete-saved"]');
    if (deleteButtons.length === 0) {
      console.log("No more saved items to delete.");
      break;
    }

    deleteButtons[0].click();
    console.log("Deleted one saved item, remaining:", deleteButtons.length - 1);

    await new Promise(resolve => setTimeout(resolve, 2000));
  }
}

deleteAllSavedItems();

Maybe Amazon updated their HTML, so the other approaches didn't work.

function deleteAllAmazonItems() {
    // This query looks for Delete buttons in BOTH the active cart and saved items
    // based on the specific selectors in your page source
    var query = document.querySelectorAll("#sc-active-cart input[value=Delete], #sc-saved-cart input[value=Delete], input[data-action='delete-active']");
    
    if (query.length > 0) {
        console.log('Items remaining: ' + query.length);
        query[0].click();
        
        // Wait 1 second for Amazon to update the UI, then run again
        setTimeout(deleteAllAmazonItems, 1000);
    } else {
        // If no buttons are found, try scrolling once to see if more lazy-load
        window.scrollTo(0, document.body.scrollHeight);
        
        setTimeout(function() {
            var retryQuery = document.querySelectorAll("#sc-active-cart input[value=Delete], #sc-saved-cart input[value=Delete], input[data-action='delete-active']");
            if (retryQuery.length > 0) {
                deleteAllAmazonItems();
            } else {
                console.log('Finished :) All items cleared.');
            }
        }, 2000);
    }
}

deleteAllAmazonItems();

Was able to get this to work, it is a little slow but was able to delete over 500 items without issue.