Fashion For Walls
Similar photos have been done before such as by the ad agency TBWA for the "Fashion for Walls" campaign. In this case they used a combination of a real model, and a mannequin was switched out, and then they threw paint buckets at the mannequin. Then in post production the two were combined.
I wouldn't say that these photos don't "involve photo-editing for the effects" rather, they don't use computer generated imagery for the effect, they just post process multiple images together.
Milk & Water
For Jaroslav Wieczorkiewicz's work, details can be found at this stobist post here. The main idea is that he used very high speed capture to freeze the water on the black background.
Jaroslav points out that the most important aspect is the concept, beyond that the actual work of putting it all together is not as difficult.
I have not attended one of his workshops where he gives detailed step by step instructions on how to accomplish works such as MILK. From what I can tell his work is a composite of many water/milk thrown images and images that are of the models by themselves on black studio backgrounds. Mix that with very high speed shots and ultra fast strobes/lights and you have the main idea.
Information directly from Jaroslav on the "Playing with water shoot": Here
Fashion for Walls info: Here