@rtenesup
If what you say is the case, it was likely that the parents misinterpreted the instructions.
Firstly, there used to be two different kinds of glycerin suppositories for kids.
For infants, there were long, thin suppositories, like these:
https://www.worthpoint.com/worthopedia/vintage-purepac-glycerin-429423324
The instructions say to insert the suppository while holding the large end in a tissue for a few minutes until it works. I think it was mother's lore to move it in and out intensify and/or speed up the results.
There were, and still are, the adult bullet or cone shaped suppositories, which are supposed to be inserted well up someone with a finger or applicator, and just left to dissolve/melt and prompt pooing.
The long, thin infant style have pretty much disappeared. I think it's likely that pushing an adult finger up a kid is now frowned upon, especially when liquid glycerin applicators are now being marketed. These applicators are a far better way to make a kid, or an adult, poo. The giver's hands never get dirty and results start within a few minutes, much faster than a suppository. There is no need at all to hold the suppository in a kid... In goes the applicator, squeeze, and remove the applicator and diaper..... all done in under a minute. Within a few minutes more, there will be results.