Hi, does the product leave a smell after being rinsed off. If so, how long does the smell last?

I don’t think they leave a smell. They are just small bleach tablets. No different than if you put a couple of tea spoons of normal bleach and rinsed.

Our bath water drains into a tank which we use to water the plants with. Are these tablets plant friendly?

They are chlorine based bleach, so I would say they weren’t very plant friendly. After all their purpose is to kill bacteria and algae in the pipes of your spa bath.

Hi, for indoor jacuzzi, would the normal bathroom ventilation enough? The instruction suggests to use in outdoor &well-ventilated space

I use it in the bathroom without problems. Just leave the door open or a window if you are worried. Sometimes there is a very slight smell while the jets are running but usually nothing.

Can I use these in an air bath as opposed to a whirlpool?

I don’t see why not. Mine is a whirlpool bath, where you can have just water circulation or water and air. They work fine and sterilise any water that’s left in the pump and pipe work, so you don’t get flecks of black algae.