It is OK to put Fabuloso in toilet tank although overtime it may cause your toilet flapper and rubber seals to degrade but they are cheap and easy to replace.
Toilet flappers should be replaced every 5 years or so regardless.
The fabuloso toilet trick is where you dump the entire bottle of fabuloso into the toilet tank directly or you can cut a hole at the bottom of the bottle of Fabuloso and place it inside the toilet tank.
Using Fabuloso in the toilet tank fills the toilet bowl with the fabuloso which helps keep it clean and smelling fresh.
You can hang Fabuloso in a toilet tank by taking a piece of stiff wire and wrapping it around the top of the bottle or by wrapping it around the bottle and creating a hook with the wire such as with a clothes hanger.
Then make a bend with the wire to hang it off the top of the toilet tank.
To use Fabuloso in toilet tank hack you dump the entire bottle of fabuloso into the toilet tank directly or you can cut a hole at the bottom of the bottle of Fabuloso and place it inside the toilet tank.
Using Fabuloso in the toilet tank fills the toilet bowl with the fabuloso which helps keep it clean and smelling fresh.
You can also clean your toilet bowl by pouring a little bit of Fabuloso into the toilet bowl and scrubbing it clean.
However it's not recommended to pour the Fabuloso into the toilet tank as it can degrade the rubber gasket and seals in your toilet tank and be corrosive.
You can also add some white vinegar and baking soda in the toilet tank or in the toilet bowl to clean it.
The white vinegar and baking soda is a natural cleaning agent to clean your toilet bowl and keep it smelling fresh and clean.
Bleach can also be used by itself to clean the toilet bowl and disinfect the toilet bowl but you should not put bleach in the toilet tank as it can cause damage to the seals and gaskets.