Most of Lasch's suggestions are well taken, and if I followed them, my writing would much improve.
He does not, however, seem to recognize that language changes. People use old words in new ways and people make new words. It happens. "Hopefully" has become, like it or not (Lasch says not), a word that means something like "it is to be hoped that." The most discouraging part is Lasch's guide to pronouncing certain words. He wants speakers to pronounce the voiceless "t" (or [t] in IPA) in the word "congratulations" instead of the voiced [d] (or, one would imagine, horror of horrors, the voiced affricate of [t]). Hint: an intervocalic voiceless plosive tends to become voiced. It's how language evolves.
I recommend Strunk and White over Lasch. Lasch doesn't really offer much new, better than, or different from Strunk and White. And Strunk and White, at least in the more recent editions, have a final chapter in which they acknowledge that language does indeed change and that stylistic prescriptions owe a great deal to conventional notions.