Jane, I think she uses the water softener and detergent as suggested in the Geo recipe, except we couldn't find powdered detergent. I think she used half the recommended amount of liquid detergent since it is more concentrated. This is on top of the standard, not green, deodorizers available anywhere, with 4 gal. of water. So what she is doing is the same as the Geo formula without the Clorox until a day or so before we flush the black tank. If it were up to me (and it isn't) I'd use less of the Clorox than recommended.
Once we feel the black tank has been thoroughly cleaned, we may not use the Geo formula all the time. We have a Flush King, so I can see what is coming out and is became reasonably clear in 5 backflushes instead of the usual 7 or 8. If there is stuff stuck in there after 4 1/2 years, it will take some flushing to get it all out.
My experience is that after a season of towing, I'll backflush the tank 10 times and it seems to be clean, but in the spring when I drain the antifreeze out into a 5 gal. bucket (this is not an enjoyable experience), more stuff comes out. So next spring I'll have a better idea how this works when I see what I get.