Questions regarding gasket rule

Hi,

I have a question regarding gasket, i know it doesn't work but , i'd like to know why.

-At the start of the battle i put canister fuel dice on the locked spot.

-Gasket can't exhaust his dice.

-I can exhaust how many dice i want of the active/locked space.

-If i have 2 canister on the locked space and i exhaust one, why i can't roll him the next turn ?

Raw i can't see anithing that says i can't,( but i know this doesn't work like this.)