The "sticky-false" class is meant for an entire row, not an individual column.
<tr class="sticky-false">
<th class="sorter-false" colspan="5">This row will not be sticky</th>
</tr>
<tr>
<th class="filter-false sorter-false">Column 1</th>
...
<th>Column 5</th>
</tr>
If you want to hide a column filter, use the following css:
.tablesorter-filter-row .disabled { display: none; }