innowed, может атрибут disabled? или так
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<script>
window.addEventListener('DOMContentLoaded', function() {
[].forEach.call(document.querySelectorAll('.qwe'), function(item) {
item.addEventListener('input', function() {
item.value=''
});
});
});
</script>
</head>
<body>
<input type="text" class="qwe">
<input type="text" class="qwe">
<input type="text" class="qwe">
</body>
</html>