Increase in saturation in natural clayey slopes along coastal zones as a result of tsunamis or storm surges may cause flow slides or failures. One of the common treatments is to increase the overall stability by soil replacement and/or re-compaction, which is often difficult to implement, expensive, and, most importantly, damages the natural vegetation. In this paper, remedial effectiveness of a relatively economical and environmentally friendly method involving insertion of geotextile strips with drainage capability into natural clayey slopes is evaluated through a series of centrifuge tests. The test results demonstrate the effectiveness of the employed technique to increase the stability of slopes and their drainage capability as well as to reduce the deformations under surcharge loadings.