Couldn't find the string in the archives for you about keeping the sprayer unclogged - but in the past, there were some good suggestions.
One I took up was to buy a very cheap little plastic spray bottle
holding about 50 mls which wears a plastic cap. After use, fill the
cap with water, invert the bottle and press the cap on tightly. I
last used my Pripps flux 3 weeks ago - and just tried it - worked
immediately. – John Burgess; @John_Burgess2 of Mapua Nelson NZ