after being frustrated with the mess of my valve on the third try due to my crappy craftsmanship I got annoyed knowing that my new gun just wouldn't cut it without (edit) a 3way 2position pilot valve(/edit). so I started to take apart one of my blowguns and realized that the piston was a lot like the piston in my attempted inside-out slide valve

(the design should be fine I'm just a crappy craftsman) so I thought of a way to make my blowgun exhaust air when squeezed it. and within minutes I made this

I raised the handle so you can sorta see how I changed the button on this

piston device in blowgun

a view of the piston, sorry that my pics suck Its hard to get a clear view of the tiny mechanisms
I haven't tested this on a valve cause I don't have the proper fittings but I did do some testing with a quick connect the only problem is that the piston wants to pop all the way up into a closed position when handle is released I can easily fix that with some kind of mechanical device that restricts the lever from raising too high, and on the bright side it has potential for a safety
Sorry if you are still unclear on this I'll try to add some more descriptions and diagrams later