If I remember correct... I stand corrected on this, cause I cannot find the paragraphs that says this online now.
If I remember correct, shifu did say that after telling a lie, you can
confess to the lie and that would help your karma. So it's not mindful, then just admit that it was a lie.
Personally, I think it's very good to confess to mistake, whether a lie or not. This would help to prevent the person for making the same mistake, may be not instantly, but over time, the person will change to stop making that mistake again.
You taken all the 5 precepts already ? Even if not, I suggest you pay attention to this
https://book.bfnn.org/books2/1029.htm#a04 五戒表解. Revise it every now and then.
I also have not taken the 5 precepts. It's history. But I watch the precept closely and try I don't offend. I don't believe I can reborn in Pureland if I still lax on the precepts. Actually, if you keep reading about it and think of the precepts, when the situation arise, it's easier to not commit the mistake.
观经 - 净业三福
第一福、「孝养父母,奉事师长,慈心不杀,修十善业」。
第二福、「
受持三皈,具足众戒,不犯威仪」。 《=== 具足众戒
第三福、「发菩提心,深信因果,读诵大乘,劝进行者」。