The verbs in my previous post are exceptions. Those verbs are not so many. Generally speaking, it's considered that ~せる/す verbs are in a process of changing from ichidan verbs ~せる to godan verbs ~す now, and it differs depending on the verb which, ~せる or ~す, is more common. Actually, "漂わせる vs. 漂わす" is an exception, too. In this pair, 漂わす is the original (i.e., it was used also in classical Japanese), and 漂わせる is the causative form of 漂う. Anyway, both ~せる and ~す somehow have a causative nuance in most cases, so the point you need to pay attention would be the potential form of the verbs I mentioned in my post above.