You should be able to use "straight talk" as an alternative.
Simple, honest speaking.
call a spade a spade
speak the truth; to say things as they really are.
Also, couple of other idioms (using the word "straight"): "straight from the shoulder" & "give it to someone straight".
straight from the shoulder (American)
if you speak straight from the shoulder, you speak directly and honestly
I gave it to him
straight from the shoulder. 'You're talking garbage,' I said.
Cambridge Idioms Dictionary, 2nd ed. Copyright © Cambridge University
Press 2006. Reproduced with permission.
give it to someone (straight) to tell something to someone clearly and directly.
Come on, give it to me straight. I want to
know exactly what happened.
Quit wasting time, and tell me. Give it to
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by
The McGraw-Hill Companies, Inc.