There's no stats for home produced stuff cos every home producer will be producing something slightly different, dependant on the uniqueness of each home producers unit's construction or configuration, combined with any ancillary equipment, methods and practices incorporated into their production process.
Not sure if that was a typo about commercial products being less effective, I'm sure they would disagree with that comment, they insist *theirs* is the best. If you know what you're doing, are happy with what you make, and it appears to be efficacious...then *that's* the best product available...it's all effective.
And that was Beck's whole idea, making it practical and affordable for anyone who wanted to produce it...until the marketers got their hands on it and started competing with each other for your money. If he were still around today he would agree also that *any* water is not good enough, he would have understood that DW is preferable, but he got people to look into making their own, and that was the main objective.