Surfactant solution transport rates were measured on wool yarn soured or otherwise treated with various nonylphenol poly(ethylene oxide)(NPEO) surfactants or with the sodium salt of dioctyl sulfosuccinate. The EO chain length of the NPEO used to scour the yarn had a significant effect on the diffusivity coefficient, although not on the residual contaminant level or the color. Surfactants applied as prewetting or rewetting agents increased the diffusivity coefficients. Prewetting gives the faster solution transport rates, and the temperature of application and the wet add-on are important. The effectiveness of a rewetting agent is related to its rate of solution.