So you suggest letting the heckler mess up your performance, rather than making them look dumb early so no one else listens to them.
No, I suggest ignoring them.
These are steps from paid Las Vegas performer Tyas Frantz, which I posted in my Heckler essay:
1) Acknowledge the heckler.
“Acknowledging the heckler” means when a heckler spots a method and points it out, just say something along the lines of, “Good eye,” and move along. But do it in a nonchalant manner, and quickly move on. Odds are they will keep their mouth shut for the rest of your performance.
2) Ignore the heckler.
This step is, I feel, pretty self-explanatory. Just act as if the heckler is not there, and either the rest of the audience will hush them up or the heckler will decide that it’s not worth it and will either be quiet or leave.
This is one step that I usually skip, because it usually ends up turning into a huge “argument” and the rest of the audience grows bored, and therefore leaves.
4) Educate the audience.
If, at this point, the heckler is still bothering you, just stop wherever you are at in your performance, and tell the rest of the audience that you can no longer perform while the heckler is in the audience. At this point, the audience usually takes care of the heckler for you by “booing and shooing” the heckler away.
5) Have the heckler removed.
Hopefully you never let the heckler get past step four, but, if for any reason, it does happen…. it is time for the heckler to leave your performance. If it is a free show, and therefore they did not pay to watch you perform, it’s practically impossible for you to have the heckler removed. However, if it is a paid performance, you are in complete control of who watches you perform, and for how long they do so… therefore you are able to take them outside, tell them they need to leave, and give them a complete refund.
So no... I don't recommend trying to upstage or out-heckle the heckler... unless your name just so conveniently happens to be Gazzo, and you conveniently happen to have been busking for a very long, long time.