although only an expert should try this, a computer guy in Canada was solicited by a scammer to send bitcoin, and he instead scammed them into showing "good faith" by depositing a small amount of bitcoin into his account

Note: this does not work with checks, since the bank can collect from you for fake checks. Bitcoin is irreversible, though.

https://www.cbc.ca/news/canada/calgary/ben-perrin-bitcoin-1.5238225