How do I Americanize "Fat lot of good X will do you"?

Question

I learned British English, but I work exclusively with Americans. I'll often say "Fat lot of good X did for us", and I get confused looks from others. For example, the other day, I said "I think we should have had them take the web development course; fat lot of good the algorithms course did for them" and people have no idea what I mean. A coworker told me that what I'm saying sounds like what someone British would say, and I'm not sure how to Americanize this statement.

First: Am I using the term "Fat lot of good" incorrectly? Second: How should I say this in American English?

Answer 1

Just leave out the fat, in speech, and use a sarcastic tone.

"I think we should have had them take the web development course; a lot of good the algorithms course did for them."

The fact is that this is an idiomatic expression.

And many Americans would in fact understand "a fat lot of good". Who cares what a coworker says? The expression is not essentially British at all.

It's in Merriam Webster like this:

a (fat) lot of good idiom informal : no use or help at all "I've brought an umbrella." "A (fat) lot of good that will do now that it's stopped raining!"

Merriam Webster

Answer 2

A whole lot of good would also work. I'm guessing the confusion comes from the fact that "fat" generally refers to being overweight.