So was informally suggested to me. (See my earlier posts about which is more min hamuvchar.) But here is an interesting Darkei Moshe on the subject matter, which I found fascinating. (Note that this represents only some opinions on the matter. For a broader treatment, see the actual sources inside, and/or Aruch Hashulchan.)
First, the Tur. We see that after the zman elapses, one can blow it out, or make use of its light. (Also see this in the Rif, who is basing himself on the gemara.) The implication is that once one has fulfilled for the shiur, they no longer are nerot chanukkah. (Aruch Hashulchan writes that some have the custom not to blow them out, and if so, hold by it, but the minhag is his area is that they blew them out -- see last seif in that siman, 672.)
On the above Tur (note א), Rama writes the what is pictured to the right. Click on it -- or the above-linked PDF, to see it larger. To summarize, in the Hagahot Semak it is written that Rabbi Shimon said to make the wicks "long." What does this mean? The answer is that there is an opinion, when there was pirsumei nisa outside (as in the time of the gemara), there was a reason to make it last a specific length. But nowadays, when lighting inside, one can take tiny candles which will only burn for, say, a minute, and light them. So then it said in Hagahot Semak to make them "long," it merely meant longer than the tiny ones, such that they would last the required shiur. And he shows how this is mashma from the language there. And if one makes them burn longer, this is not for any need, and it is not even hiddur mitzvah, for after the appropriate shiur, they are permitted in benefit, and there is only hiddur mitzvah at the time of the mitzvah.
(One might counter that since one could light later and still fulfill, this is the time of the mitzvah. But his point, I believe, is that after the shiur, it has been fulfilled, and there is no more mitzvah or "time of the mitzvah" as regards the lighting of these candles.)
Still, see Aruch Hashulchan (again, last seif) who says to use long candles, because this is more noy. Thus, it is an issue of beauty, rather than of length.
So if we rely on this Rama, oil is no better than wax in this regard.
Note: Though I think candles are nicer, for reasons I went into in prior posts, none of this is intended halacha lemaaseh. Consult your local Orthodox rabbi.