Does a threat or exhortation by the police that it would be better for the accused to tell the truth be considered involuntary?

Similarly, the " 'mere advice or exhortation by the police that it would be better for the accused to tell the truth when unaccompanied by either a threat or a promise does not render a subsequent [statement or admission] involuntary.' [Citation.] In terms of assessing inducements assertedly offered to a suspect, ' "[w]hen the benefit pointed out by the police . . . is merely that which flows naturally from a truthful and honest course of conduct," the subsequent statement will not be considered involuntarily made. [Citation.]' [Citations.]" (People v. Howard (1988) 44 Cal.3d 375, 398, superseded on another ground as recognized in People v. Shoemake (1993) 16 Cal.App.4th 243, 253.)