I clean out my Hysol nozzles by taking a little plastic tubing and a syringe (without needle) and flush it with Acetone. I use a jar filled with Acetone and draw the syringe full, then connect the tubing to the Syringe and nozzle. Then flush the nozzle into the jar containing the Acetone. I then refill the syringe and flush it again. I then just leave tube connected and draw and flush through the nozzle until clean.
I have be using the same nozzle for several years. and half a dozen or more planes.