Can sex dolls be made to cough up more lube if their mouths are fucked too deeply?

I’m sure they can be made with a “Lube sack” somewhere in the head. But the creation and cost-effectiveness would play a part. When you fuck the mouth, the force in the mouth will push the button on the back of the throat and make lube substance flow from chambers. There could also be two in the cheeks, as the saliva glands. The only issue is having real tubes in them to keep the lube from leaching into the doll while the “sack” is full and the button has to be some type of air pressure that pulls it in (maybe through the noise) but it’s one-directional, so the air goes into the sack as it empties, so all pushes always release lube till the “sack” is empty.