What's the best upholstery glue?

We've always used Clair's adhesives.  I get them from the local trim shop.  The LL Landau Top adhesive works the best for me.  I've had it on panels for years and still had trouble pulling them apart when I got ready to redo.  I've used most of the others mentioned and they all released after a while.

The smell of the green glue is the best part!  I use it for headliners, door panels, sub boxes, anything that needs glue.  its contact glue so u have to spray both sides really good and let dry for a couple minutes.  It sprays fine out of a harbor freight air gun.  its just my 2 cents.  I install sunroofs and leather in brand new right of the truck cars and trucks and have to make door panels and headliners last for years like factory.  I never had a problem with air bubbles or the shit seperating ever and im not exaggerating.  WELDWOOD better give me some free glue for this advertisement those bastards!

What would you use to clean the glue out of a non disposable gun after use?