[folivier]

It may be easier to add a sintered brass filter or some other type to keep the trash out.
https://www.amazon.com/PneumaticPlus-Bra...DVCJ39TB3P

I've always had the thought that one of the reasons for the 6-pack solenoids failing is because of trash cutting the sealing surfaces. But as it's a closed air system that shouldn't happen, but as you've just demonstrated possibly trash is getting in through the exhaust port. Who's gonna be the guinea pig and add an exhaust filter to the 6-pack exhaust?
Don't make me buy another Newell just to prove my theory....