In this paper, we study the performance of a practical secret key generation method under low-mobility scenarios. Instead of relying on traditional cryptographic methods or leveraging spatial diversity and reconfigurable intelligent surfaces to increase channel variations, we utilize locally generated pilots to add randomness to the system, thus in turn helping to increase the secret key rate. The results demonstrate significant improvements over the original channels, whose entropy source mainly relies on mobility and channel variations. More importantly, this scheme works well without extra helpers or multiple antennas, thus providing a potential for developing reliable, lightweight security solutions for resource-constrained devices in practice.