EFFY?
I could not disagree more so perhaps will agree to disagree. I don't use chemicals, I don't like them as they wreak havoc on the environment and the perfumes they use cause issues with my lungs and sinuses. I only use water and as has been stated many times by seasoned Rver's who only use water and none of us have an odor issue. Not sure what your issue is, but you may want to check it out. Smelly chemicals don't fix anything. They simply mask a problem with perfumes. I prefer to get to the root of a problem and fix it rather than cover it up. But to each his own. If you are so bent on using chemicals knock yourself out. But if you are looking for validation that it's ok, you may have to look elsewhere.
The product I use is totally all natural.I don't have a problem at all hardly ever unless Like I have said 14 times now The tank gets too full on a warm day and the indio winds are blowing the wrong way or I left the Bathroom vent open then in these conditions I do get a
wiff of sewer. AS said all Black tanks will have odours, now if your vents in a area where it does not effect you either by roof vents or
whatever great but believe you me theres odour coming from your 3/4 full Black tank just the same as everyone else that has a RV
to say theres no odour is truly false. To say you don't experience such ever I will agree and your lucky.I have a few times and when I do I know to dump,rinse and add my chemicals