I accidentally copy and pasted something wrong just to discover it worked. That said, I am by no means an HTML expert so I don't know what the consequences of my code are, like what will break if I try to select the element's innerHTML or value. Anyway, here's my strategy:
<form name="mainForm" id="mainForm" class="mainForm">
Email:<input type="email" name="emailBox" id="emailBox" class="userInput" placeholder="Enter email address" form autocomplete="off">
the "form autocomplete="off" at the end seems to break the autocomplete, but I'm not sure what else will be messed up. Let me know if it works for you please! Or if you can see the bugs this strategy is likely to cause...thanks!