Clogged Chemical Pump Sprayer Hose Nozzle

I have a pump chemical sprayer and it has become clogged. I have tried everything I can think of to unclog it. Including the instruction booklets suggestion of filling it with warm soapy water and pressurizing it.
I have tried almost boiling water and I could feel the tubing fill with the hot water.
I tried bleach in the water.
I tried window cleaning fluid.
I am considering using straight vinegar next and I know it is a great mild acid.
Everything eventually comes out if I leave the sprayer end in a bucket........
I really need to spray my roses for rust and mildew ASAP!! Help!