Sprayer won't spray:

Usually when we hear this the batteries need to be put in the other way.

Sprayer not spraying/misting like when I first got it:

Try a fresh set of batteries

Sprayer filter is clogging:

It is supposed to.  The filter at the end of the hose is designed to protect the pump in the sprayer. Strain any grainy/seasoned liquid before putting into the bottle.