We have studied the use of a metallic pipe with small corrugations for the purpose of passively dechirping, through its wakefield, a short, intense electron bunch. The corrugated pipe is attractive for this purpose because its wake: (i) has near maximal possible amplitude for a given aperture and (ii) has a relatively large oscillation wave length, even when the aperture is small. We showed how the corrugated structure can satisfy dechirping requirements encountered in the NGLS project at LBNL[1]. We found that a linear chirp of _40MeV/mm can be induced by an NGLS-like beam, by having it pass through a corrugated, metallic pipe of radius 3mm, length 8.2m, and corrugation parameters full depth 450um and period 1000 um. This structure is about 15 times as effective in the role of dechirper as an S-band accelerator structure used passively. Show Partial Abstract