The increasing availability of digital 3D environments, whether through image reconstruction, generation, or scans obtained via lasers or robots, is driving innovation across various fields. Among the numerous applications, there is a significant demand for those that enable 3D interaction, such as 3D Interactive Segmentation, which is useful for tasks like object selection and manipulation. Additionally, there is a persistent need for solutions that are efficient, precise, and consistently perform well across diverse settings, particularly in unseen environments and with unfamiliar objects. In this work, we introduce a method that consistently surpasses previous state-of-the-art techniques on both in-domain and out-of-domain datasets. Our simple approach integrates a voxel-based sparse encoder with a lightweight transformer-based decoder that implements implicit click fusion, achieving superior performance and maximizing efficiency. Our method demonstrates substantial improvements on benchmark datasets, including ScanNet, ScanNet++, S3DIS, and KITTI-360, and also on unseen geometric distributions such as Gaussian Splatting.