Three Good Reasons to Use Muck Munchers

We have large (ish) 3-chamber septic tank and usually only two people in the house. We have used muckmuncher sachets for 11 months. The tanks were emptied before we started using the sachets. It is difficult to be scientific, but I get the impression: a) the final outflow of liquid is cleaner (but not clear) than it used to be; b) the scum on top of first tank is an even dark colour (more so than previously); c) smell is less.