There was a time when I was going to design my humanoddball.com website as an outlet for various graphic design tools. In the process of developing that site (which ended up as something completely different), I started a secondary deviantart.com account at http://humanoddball.deviantart.com/.
The following are two of the Photoshop brush sets from that account – 25 Large Watercolor Splats and 35 Watercolor Splats. Hopefully you can find a purpose and use these in your work. No need to attribute me on these – just go ahead and Photoshop away.