Ditto. Daily use = zero odor. Can't picture how to get anything easily introduced to the intake. But, most importantly, your method will kill all beneficial bacteria in your holding tank that actually decompose the waste and keep it from smelling over time.
I add some Raritan KO with the first flush after emptying the holding tank. It's a bio active tank treatment, not a nuclear assault. From there, we have a hard and fast rule, nothing goes down the head unless you ate it or it's the TP provided.
I remove the intake hose end from the thru hull, put it in a small paint bucket filled with peroxide and pump. I work out of town and can only get to the boat on weekends. In the Louisiana summer the H2S smell gets pretty bad and doesn't go away on first flush. This is the first thing I've tried that works. I pump out the holding tank frequently so I'm not worried about bacterial content of the brew.
Hydrogen peroxide is H2O2, water with an extra oxygen atom and decomposes rather quickly even just sitting in the bottle. In killing the small amount of bacteria in the inlet water most or all gets consumed so nothing is left to kill the massive amount of bacteria in the holding tank.
In cleaning our large waste treatment plant membrane filter we use much stronger solutions of bleach and hydrogen peroxide and dump it right back into the bioreactors with no problem.