That sounds like a big waste of money (I don't think the mixing is even close to 5%) and also just more trouble for the sewage processing plants (which rely on bacteria to clean the sewage!)
Reckon so, but I gather the purpose isn't to kill bugs in what's flushed only those in the
the airborne aerosols.
I use the spray type for bathroom tiles etc. but seeing every supermarket sells a squirt nozzle variety for toilet use it's worth asking whether it's actually effective at killing the aerosol bugs. If it is then I might consider using it.