Have you tried Micro Applicator brushes yet?

[ScottsGT]

Somewhere, sometime in my modeling career I managed to get a small sample of micro brushes.  Went into my drawer of tools and hobby junk to be forgotten about.  During my new bench build and reorganization I dug these out and put them in one of my new parts/storage bins on my bench.  Pulled one out on a whim to place CA glue on a very small area. All of a sudden I have discovered a new useful tool I don’t know how I've been building without them. 
And now I needed to know where to find more.  Amazon of course! Advertised for makeup application, car detailing, etc. .  If you haven’t tried these, do it! 
https://www.amazon.com/dp/B01M0QAYOL?psc=1&ref=ppx_yo2ov_dt_b_product_details

[DocRob]

I tried them on several occasions, but was always disappointed by the results. To my eye, there is nothing, they do better than a good sable brush. Especially their paint holding capacity is next to none. I thought, I could use them for very fine details, but again, no advantage to either a good paint brush or, if the detail is too small, a toothpick.
The last I have are only used for pigment application as an addition to cotton swabs, which are better, but not useful in tiny hidden spots.

Cheers Rob

[Martinnfb]

Sharpened styrofoam works for me.

 

[smitty44]

I bend a small loop in thin copper wire 

[ScottsGT]

I’ve actually not tried them with paint.  Just used one to spread micro sol liquid masking over some tape joints.  So far getting tiny globs of glue in the right spot seems to be my best use of them. 

[ScottsGT]

Discovered another use for them last week.  I had sprayed white lacquer into the wheel wells of my latest build and I forgot to plug the holes to keep paint out of.  
Dip the micro applicator in some lacquer thinner and wipe out the paint in the holes.   Had to act quickly though. The thinner was dissolving the glue that holds the fuzzys on the end of the stick.  Used one to get the thinner in the hole, another to wipe it clean. 
A cotton swab wouldn’t have even come close to fitting in the hole.