When Maura is showing off her new saber grip she makes two mistakes. She refers to it as a "handle" when the correct term is "grip", and when she flourishes it, she is using the stance and motions characteristic of a foil or epee fencer, not a saber. Later, when she uses her fencing moves against the cornered suspect, her stance and motions are also those of a foil or epee user, not a saber fighter.
Maura says glycerin is only available through commercial sources so she hypothesizes the killer boiled down fat to extract it. Glycerin is easily bought in any drugstore or grocery store that sell health and beauty products. There is no need to go through that big rigamarole she described, it is unnecessary and nonsensical.