This sounds a bit silly to me. While I've had some females reabsorb follicles, I've only had one female ever slug out, and one partial slug clutch. In 5 years, that's all. The rest of my clutches have been entirely fertile, with just the occasional single slug here and there. I've never mucked around with my males like that before pairing them--it sounds stressful for them. I know they certainly don't enjoy being popped, and doing it so often is likely to cause discomfort.
I have heard the trick about wiping a good breeder's sperm onto a female to inspire a lazy male, but haven't had the opportunity to try it, yet--I've never had a lazy male.
"Sperm plug" isn't really right, anyhow. In general, a sperm plug is something you would find in a female, after a male has bred with her, and its purpose is to block other males from successfully copulating. Ball pythons don't produce sperm plugs. The little stringy things the male produces are just bits of dried and partially dried semen caught in the hemipenal pockets, they aren't plugging anything.
I know it's in common use--perhaps the mistaken use of the term has confused a few people.