If you need to put anything in the rinse cycle to eliminate BO from your clothes, somethings majorly wrong with the detergent you're using and/or your machine. I've had my Electrolux front loader since '08 or '09 and never had any issues with "front load must". Here's what I do:

Use a quality detergent; Tide Free & Clear, it's worth it, you don't need much. Bleach my whites. For bulky items like blankets that don't get laundered often, I use the 2 hour "deep clean sanitize" cycle. It gets REALLY hot, like when the drum isn't moving, you can hear the "sizzle" of the submerged heating element. This probably helps break down scum and stuff. There's a product called "Affresh" specifically made to "remove odor causing residues and grime daily loads leave behind." It comes 6 tablets to a pack, and you're supposed to run one tablet a month through it. Screw that noise. Once a year, if that, I throw in the whole box and run the sanitize cycle. Still works as good as the day I got it. And it doesn't even have Wi-Fi.