We demonstrate Rock, a system for cleaning relational data. Rock highlights the following unique features: (1) it extends logic rules by embedding machine learning models as predicates, to benefit from both ML and logic deduction; (2) it supports entity resolution, conflict resolution, timeliness deduction and missing data imputation in a unified process; and (3) it provides parallelly scalable algorithms for rule discovery, error detection and error correction, in batch and incremental modes. We will demonstrate Rock for its (a) easy-to-use interface, (b) scalability when cleaning large datasets, (c) accuracy for detecting and correcting errors across multiple tables, and (d) applications at banks and HR departments.