I recently purchased an RG20051, which is Ibanez factory-swirled guitar supposedly done by the same artist who did the MKR swirls for the UVMC. I took some closeups of the guitar that might help you.
Here's what I can tell from looking at the guitar. Many of the swirl attempts I see on here seem to come out of the tank with a fairly lumpy finish. The swirler then tries to hide this by building the surface up level with multiple layers of clearcoat. On my guitar, the swirl part of the paint appears extremely level. My guess is that the paint is thinned down quite a bit. If you look at the pictures below, you can see quite a lot of detail in certain areas that could only have been achieved with very thin paint that could mix pretty thoroughly.
This first picture shows a spot where there's a chip next to the trem. I've tried to show the thickness of the clearcoat (which is quite thick), but that may just be the nature of the polyester clear coat Ibanez uses, which may just have a very high build.
Extreme closeup shows better detail of chip:
Second shot showing more fine detail in the swirl
Extreme closeup. If you look carefully, you can find a fisheye from where a water droplet dried. There are a few of these in various spots on the guitar.
Other ideas I would try would be basic tricks from painting a car.
1. Prepare the guitar with a base coat and then get that coat to a 600 grit finish. When you paint a car and you go from primer to your topcoat or anytime you're in between coats, you sand to a 600 grit finish. This not only levels the surface, but promotes adhesion of the next coat. The scratches are fine enough that the next coat fills them in and still levels perfectly above them without leaving visible scratches.
2. Put a static charge on the guitar. Car manufactures paint this way. Basically, a static charge is put on the car body which causes the paint to attract to the body. This may or may not work, but it would be worth a try. You could rub the body with something like a rabbit pelt (remember your grade school science class?) and it might draw the paint in off the surface of the water to the guitar, giving you better coverage despite using very thin paint.
Another thing I would pay attention to is your dip tank and your water. The quality of the water will vary greatly from place to place and would have a big effect on how the paint floats and how well the water would sheet off the guitar when you're done. Hard water will tend to stick to the surface and leave a lot of droplets, which could lead to a bunch of ugly fisheyes. I'd consider getting a ton of distilled water and dipping the guitar only in that. I'd also get a quality detergent like Alconox and clean your whole dip tank thoroughly with it, then rinse with distilled.
