This paper highlights the importance of proper initialization techniques for simulation model stability and computational efficiency. A generic initialization method called Decoupling Interface (DI) is proposed. It is applicable to any MTDC grid component. The method is tested on the CIGRE BM1 and BM7 benchmarks in a tool for the simulation of electromagnetic transients (EMTs). Compared to an existing load-flow initialization technique, DI reduces the initialization time by 41 and 16 times for CIGRE BM1 and BM7 test cases, respectively. Furthermore, the paper demonstrates DI's ability to prevent initialization failures in the CIGRE BM7 system.