You will need grams of Valerian. It takes 4-6 grams of Valerian by itself to cause significant sedation. This amount of Valerian is not hard nor expensive to come by. It does not rapidly build tolerance.
You should have extra sedation and euphoria. It will not last nearly as long as the benzo you take.
This should really be only a booster as you say. I forewarn you that this is going to be the worse memory deprivation ever. You will sleep very deeply if you pass out or crash.
Note: Please do not drink alcohol on this much Valerian. Valerian blocks your ability to metabolize alcohol at the same time adding to it's effects.
Further Note: Please do not get the calming mixture which also contains Passion Flower extract.
This is very dangerous for people wanting to use Valerian plus Passion Flower Extract for stimulant comedowns (Passion Flower contains MAOI's) Also, you will poison yourself from this much Passion Flower extract.