manipulation of cash flows vs sales

Schweser says cash flows are easier to manipulate than sales. how can this be?

I don’t know about that. Seems pretty easy to manipulate either of them. For example, suppose you are Ford Motor company. You can manipulate sales by offering dealers incentives to take your cars and then agreeing to buy them back if they don’t sell. You book all those cars as sales even though they might all come back to you. There are lots of ways of manipulating cash flow by moving stuff between operating and investing cash flow. For example, companies have tried to capitalize everything in the world which takes a hit from operating cash flow and moves it into investing cash flow. Completely manipulating cash flow is a little harder but you do things like pay your bills late, sell receivables, reverse reserve accounts (I like that phrase “reverse reserve” as it reverses an r and s - it’s sort-of represents some kind of step toward Zen enlightenment or something).