There are many ways to express the physical act of beating someone up, without resorting to crude or violent language. Synonyms for "beat someone silly" include, among others, "thrash," "bash," "pummel," "maul," "bludgeon," "assail," "attack," "thump," "wallop," and "club." Each of these words has its own unique connotations, so it's important to choose the right one for the particular situation. For instance, "pummel" suggests an extended barrage of blows, while "bludgeon" implies a heavy, blunt instrument. Ultimately, finding the right synonym depends on the tone and context of the sentence, as well as the intended impact on the reader.