Ah... so it's really a low flow blowing off the pieces kind of operation...
How about actually vacuuming rather than blowing?

Could probably glue a PVC cap on the end of the shop vac hose and drill a hole in it for a 1/4" NPT fitting.
That would probably work either direction, pressure or vacuum.

__________________
On some nights I still believe that a car with the fuel gauge on empty can run about fifty more miles if you have the right music very loud on the radio. - HST

1983 300SD - 305000
1984 Toyota Landcruiser - 190000
1994 GMC Jimmy - 203000

https://media.giphy.com/media/X3nnss8PAj5aU/giphy.gif