US wire transfers generally can't be reversed --- sometimes, if an error is noted immediately, and the destination bank cooperates, they'll send the money back; but the recipient can pull cash out immediately or wire the funds somewhere else immediately, and then your recourse is through the courts. ACH transactions are like checks; they can be reversed, but only if there was a mistake or they were unauthorized, not because of a service complaint; again, if you have a service problem, recourse is through the courts.
Being ashamed of an impulse purchase certainly counts as a reason to regret-- and potentially request a chargeback for-- such a purchase.
Also a chargeback is what the bank does to the merchant. From your perspective as the end user, you don't do a chargeback. What you do is you complain to your bank and they decide how to proceed from there.
Also: no-reason chargebacks are absolute BS. I worked on a PSP for a largeish adult entertainment business, and I remain convinced that most porn chargebacks are a case of "post nut clarity".