That article is full of terrible advice. I already had an argument in a different thread about Marshall & Sanow so instead I'll point out that he uses and recommends Glaser, both blue and silver, for a bedside revolver. Glaser Silver, when fired through drywall does not break up and instead acts like a solid projectile and penetrates ballistic gel deeper than it does in bare gel.
https://web.archive.org/web/2008101...sfetcher_evaluates_9mm_Glaser_Safety_Slug.pdf
One should fire a significant number of their chosen defensive rounds before trusting them and not just 5-10. I just added an RMR to my CORE pistol and will be firing at least another magazine through it to verify functioning and that is probably far fewer than I should, but I've already fired multiple magazines without it.