«Lā fīhā ghawl» does not logically assert that every other drink or place must contain a harmful effect. A comparative rhetorical implication must not be mistaken for a universal assertion about all alternatives.
Analyze it in two stages. First comes the negative proposition: this drink has no such harmful effect. Second comes the rhetorical contrast that distinguishes it from drinks for which that risk is relevant.
Keeping the negated predicate separate from its contrastive implication avoids an overstatement of what word order alone proves.