I use Carl Goldberg's Instant Jet as my preferred fast setting ACC.  These photos show how I prepare the bottle for use.

I have snipped off the very tip of the Carl Goldberg Instant Jet bottle and inserted about 3/4 inch of a 3 inch piece of Hot Stuff tubing which is a very thin, hollow flexible tube designed for dispensing ACC.  I have begun winding thread around the joint where the tubing comes out of the bottle's tip.

Here I have started winding a heavier size of string around the joint.  But sure to get about 1/2 inch of the Instant Jet tip covered by the string and about 1/4 inch of the Hot Stuff tubing covered as well.

After the thread is in place you will need to get some of the ACC onto it to stiffen it and hold it in place.  By holding the bottle in this position a small amount of ACC will flow out of the bottle and into the string.  Let this dry.  You can also apply the ACC from a second tube of Instant Jet if you prefer.  It's a little easier that way if you have the extra bottle of ACC.

If you find the joint leaks when you use it, you can rub some talcum powder onto the string and apply a little more ACC to make a better seal.

This is what the finished applicator looks like.

 To use, simply turn the bottle upside down and let a drop of ACC flow out of the tube.  DO NOT TOUCH THE TIP OF THE TUBING TO THE MODEL.  If you touch the tip to the model the tip will probably plug up.  If this happens you can then simply slice off a 1/16th inch piece with an Xacto knife.

When you are through for the day, put the Instant Jet into the freezer compartment.  It will last for years in the freezer and always be instantly available to use.

When you have used up the entire bottle of ACC you can simply remove the whole cap assembly and screw it onto the next bottle.

I find I have to make a new tip about once every two or three years.