The phrase "six of half a dozen other" is an idiom that means two alternatives are equivalent or interchangeable. If you want to avoid using this phrase or want to express the same idea more clearly, there are several synonyms that you can choose from. For example, "similar" or "comparable" are good alternatives that indicate the two options have almost the same value. "Alternate" and "interchangeable" represent options that can be used interchangeably. "Equal" and "equivalent" indicate that the two options have the same value. Other good synonyms include "similarly effective," "near identical," and "equally good." By using these synonyms, you can convey the same meaning without relying on the idiom.