K-dawg
The "dot" filter method or "fading" as it's sometimes called (depending on the application) uses almost no liquid carrier, only enough to spread the oil or enamel paint around. The premixed liquid filters from my understanding should also be applied as dry as possible by unloading the brush on a cloth so that only a thin almost transparent veil of paint is laid down form the damp brush. There shouldn't be any puddles deposited on the model that can collect in recesses.
If you really want the low down on Filters check out this link to Mig Jimenez's article.
http://missing-lynx.com/rare_world/rw02.htm
If I may add to, and expand this discussion?
The "Dot Method" is not necessarily applied with a low proportion of thinner. When I used it on my Hetzer build here a couple years ago--and SINCE then--I applied it with copious amounts of thinner to dilute the colors so that only a thin sheen of them remained. In fact, you rather almost try to wash the color off the model, and what remains is what constitutes the "Dot-filtered" effect. This is because the Dot Filter technique came from Spain, where the bright colors in the application--primary colors, all, basically--are intended to simulate the bright colors of the sun and the refraction of the environment on a given painted surface. Its intent is not really to "weather" as such, but instead to hint at subtle chromatic hues and differences around the model's surface. I know, I"m nitpicking, bur that's how it started in "Armor magazine".
With apologies to my good buddy wbill76 (and we've discussed this before, so don't kill me, Bill! 
) applying "dots" with natural weathering colors--Dark Umber, Tan, etc--is not really what the strict term "Dot Filters" was intended to be. When it started it was a direct juxtaposition to the "Nordic Method" which featured weathering using a lot of harsh white and Black derivatives to make harsh shadows and hues. In essence, "Dot Filtering" is as much about the colors you use as it is about how you disperse them.
"Filtering" can be applied in either thin layers or not. In conversation with Adam WIlder, he has related how he tips the model on its side and then lays on a puddle of thinned paint-a technique that I used in my Sdkfz 251 Ausf D mit Shwebelafette, (the article and explanation of it which is probably still available in the June 2010 back issue of FSM.) Or, it can be added sparingly for more subtle effects. When wbill76 lays down dots of weathering enamels and blends them in in his excellent WIP posts that we have all seen, that is filtering. Using dots. 
Think of Filtering in the same way that you'd think of a filter applied to a camera lens. It can be heavy or light, It can change the color subtly or more radically if desired when built up in layers. What you're essentially doing is filtering the light that refracts from the painted surface and gives us what we consider to be "color".How much you layer on affects the final perception of that color in the end.