On those occasions where I have furnished a wrong answer to a question on one of the SE sites and that answer has been accepted, I find I cannot go back and delete the answer. I instead edit the answer, deleting the original text and inserting words to the effect that the answer was wrong and inviting the correct answer to be provided by someone else. Is there an accepted technique for accomplishing this that I do not know about, or is my way OK?
No, this is not an acceptable way of dealing with the situation. Specifically, you shouldn't delete the original text of your answer.
The best thing to do, if you can, is to edit the answer to make it correct. Generally edits shouldn't substantially change what an answer is saying, but when the answer has been accepted you can take a bit more latitude to change it from a wrong answer to a right answer.
If you can't edit the answer to make it correct, I suppose it's okay to edit in a brief notice at the top saying that you think the answer is wrong. But you should leave the original answer there as well.
Either way, if you find yourself doing this regularly, take it as an indication that you need to be more careful to verify the correctness of your answers before you post them. (And other people also need to be more careful to verify their correctness before upvoting or accepting them, but that's not a problem you can do anything about.)
In some cases (rarely), the moderators might be willing to delete an accepted answer for you, but we'll typically only do it if there's reason to believe the answer was accepted under false pretenses - for example, if the asker accepted the first answer posted regardless of its correctness, or if they accepted an answer because they're trying to gain favor with its poster, or something like that.