An accessory for oscillating power tools includes an attachment portion with a rear end couplable to an oscillating power tool and a working portion coupled to the attachment portion and extending along a tool axis. The working portion includes a cutting edge arranged asymmetrically relative to the tool axis with a leading tooth disposed at one end of the cutting edge at a first distance from the rear end, a trailing tooth disposed on an opposite end of the cutting edge at a second distance from the rear end that is less than the first distance, and a plurality of intermediate teeth between leading tooth and the trailing tooth, each disposed less than or equal to the first distance and greater than or equal to the second distance from the rear end, the cutting edge slanted at an acute angle to a line perpendicular to the tool axis.