With acrylic being a fast drying paint, I had a problem with the paint nozzles getting clogged too easily. That must be why Liquitex offers a pack of nozzles you can purchase, but they are pricey at about $1 per nozzle and it didn't solve the clogging problem.
I'd tip the can upside-down and spray propellant to clear the nozzle as is done with the solvent based spray cans, but with a can of Liquitex spray being about $12 ea. I hated to waste it. I went as far as tossing the nozzle in a bowl of water after each spray and putting it against my lips to blow air through it. It did extend the life of the nozzles, but was not an effective solution.
That's when I stumbled upon the answer while at a local Walmart one day. There are glass cleaner aerosol spray cans that use the same nozzle type as does Liquitex. After spraying, pop your nozzle on the glass cleaner can and spray the cleaner through the nozzle into a trash can to clean it.
Simple is good. :)
Stoner's Invisible Glass Cleaner.
Found at the Walmart auto section.
Tip: When removing or installing a nozzle on a can, don't just pull it off or press it on. Give the nozzle a little twist when doing so. It comes off and installs much easier that way.