If you are soldering with paste, a stencil makes life a lot easier. Sure, you can apply paste by hand with a syringe, but a modern PCB might have hundreds or even thousands of pads. Like a lot of u… ...

This "idiot proof" thermal paste stencil makes CPU installation easy. Whether you're building a gaming PC with an Intel or AMD processor, ... Why fret about slipping with your syringe, ...

FWIW: After I use solder paste syringe, I dip the end in few drops of liquid flux and withdraw the plunger ~ 2mm to suck up a small qty of flux wetting the end and lasts several months.