A better knowledge base and a cleaner stack is its own reward. Editors aren't expecting any thanks, and there's no need to thank them.
But it is nice to be appreciated, and you'll think of leaving a @mention -ed comment on your post thanking them for the edit. We are more lenient with "thanks" comments, as @SevenSidedDie explains that "thanks" comments are valid as good feedback for the edit. However, they still do tend to get cleaned up, especially when the post is attracting more comments, so don't expect them to last long.
I have also experienced getting an inbox ping on a deleted comment, as @thedarkwanderer suggests, you can @mention the editor in the comments (even if their name won't show up in the autocomplete, thanks @doppelgreener). However, the text the pinged user can see is limited to a few characters, and I cannot totally vouch that a user gets the ping 100% of the time, and how long it will last in their inbox.
Alternatively, you can drop by chat, @mention the editor and say thanks there. This will only work for users who have been in chat for at least a week (most editors check in sometimes, anyway), you'll know that the ping will work if it auto-completes.