If you are in a setting when donations or payments are expected, a button can pass in the moment and easily be explained if detected and an explanation becomes necessary.
“Who put these buttons in the offering plate today?” I asked, holding
the buttons in the palm of my hand.
A tiny little girl with big green eyes, bigger now because of her
fear, slowly raised her hand.
“I did, Brother Jim.”
“Why did you do that?” Apparently, she heard the disapproval in my
voice. Her big green eyes filled with tears.
With her voice breaking, she said, “I didn’t mean to do anything bad.
I just wanted to make an offering to God, like you said we should. But
I don’t have any money like the other people. So I asked my Momma what
could I give and she gave me those buttons from her sewing box. She
said maybe somebody could use the buttons to help someone make some
The mother's explanation was meant to give the girl enough confidence to pass off the button, and avoid shaming the family for not having enough money. The pastor was not convinced by the mother's story, but he knew the girl was and meant it.
Clearly, a button can only hide amongst enough real coinage.
If you only pay in buttons, you don't pay enough real coinage to hide it amongst, it means that you can't properly hide that you aren't paying, and your inability to pay is obvious.
If you can afford to arrive in horse and buggy, you ought to be able to afford to pay, so there's nothing to hide or excuse that failure.