Two weeks before Christmas, Apple loosened its rules and allowed an off-color novelty app called Pull My Finger into the iTunes App Store.

The floodgates of propriety having been breached, there was no holding back. Less than a week later, VentureBeat’s MG Siegler reports, Apple approved 14 similar apps in a single day.

Today, by Siegler’s count, more than four dozen sound-effects apps not suitable for polite company are stinking up the App Store best seller list, which on Christmas Eve was topped by a program that produces — for immediate amusement or delayed gratification — pungent sounds with names like Jack the Ripper, Howard the Duck and The Sick Dog.

The developer of this noisome program, Internet entrepreneur and author Joel Comm, has atoned for his sins by publicly releasing his sales figures. The chart makes for interesting reading, as it documents the snowball effect (to mix a metaphor) of rising high enough in Apple’s Top Paid App list to get the attention of the broad app-buying public.

Here, via MacRumors, is the record of Joel Comm’s rise to the top:

12/14 – 841 units – #76 overall

12/15 – 1510 units – #39 overall

12/16 – 1797 units – #22 overall

12/17 – 2836 units – #15 overall

12/18 – 3086 units – #10 overall

12/19 – 3117 units – #9 overall

12/20 – 5497 units, – #4 overall

12/21 – 9760 units, #2 overall

12/22 – 13274 units, #1 overall

Note that sales accelerated once the program made it into the top 5. Note also that at 99 cents a pop, JoelComm is netting more than $10,000 a day. Apple’s (AAPL) cut is better than $3,000 a day.

No wonder so many third-party developers can’t seem to contain themselves.

But they better move fast. Like all novelty trends, this too will pass.