Meijer and Walmart store brands of cheap ass white bread are 22 slices, Kroger is 21, and for a name brand example Sunbeam is 22. Nicer bread like Pepperidge Farm or Brownberry/Oroweat tends to be in the range of 16 slices per loaf (baring the thin sliced stuff) though.
I like the taste of Malta fine but I find it super sweet. I imagine adding sweetened condensed milk doesn’t help that at all.