Recommend a hand held liquid sprayer for something like brake cleaner. has to be durable and not too big. A "straw" for aiming would be a bonus. No battery operated. Hand pump not required.
I have a Sure Shot mainly for Brake Cleaner and it is awesome.
I still keep a case of aerosol brake cleaner in the shop because the Sure Shot unit is a little larger and heavier, and sometimes an aerosol is a little easier to use in tight spaces, but for the most part I am a huge fan of the Sure Shot purchase.
I buy brake cleaner by the gallon which is also a bit better cost wise and I can put many different things in it if desired.