Agreed. Sklansky talks about making small mistakes early to encourage your opps to make bigger mistakes later (postflop). Showing looseness preflop is one way to do this.

at lower levels most players assume that preflop looseness means postflop looseness. Strong players understand the difference. So depending on the level, yes, this approach can lead to looser calls postflop.

One warning is that you want to be careful to encourage lots of people to be gunning for you in a tough game, unless you are prepared to keep them honest and fight back.