I used to use old plastic mustard bottles to apply my ballast glue. Now, I've found that I have more control using the squeeze plastic ketchup/mustard bottles that small burger shops use. They have a smaller tip than the mustard bottles, and since you can see through them, you can see if the glue has settled to the bottom. Another advantage is that the tip doesn't clog and jam like the twist top caps. And I can still glue a 3 foot section in less than a couple of minutes. The most tedious part is still making sure to get any loose ballast off the top of the ties. I found that a couple of gentle taps on the rails with a paint brush handle works.
Marlon
See pictures of the Clinton-Golden Valley RR