Slippery-liquid-infused porous surfaces (SLIPS) are state-of-the-art materials owing to their excellent properties derived from their fluidity (e.g., dynamic omniphobicity and self-healing function). Although SLIPS have been multifunctionalized and developed for various applications, the fabrication process is not well advanced because it is time-consuming and requires multiple steps. Here, a versatile method is reported for the instant formation of slippery surfaces in situ. A lubricated fiber-filled porous sheet was designed, and a coating was formed simply by sticking a surface to the sheet. This sheet can be used as a "disposable instant coating kit" and be made available for instant and repeated coating of SLIPS. The technique is applied to a transparent antifouling endoscope lens as a proof-of-concept. This work improves the fabrication process of SLIPS and contributes to the practical use of SLIPS.