Recently we have had some questions that could be trivially answered in the comments. Even though it is frowned upon on larger sites, it seems to be a part of Chemistry SE (I am guilty of doing this on multiple occasions as well). Now, once the OP understands the answer, I currently place a comment stating:
If you feel you've gotten an answer to your question, feel free to self-answer. they are encouraged and gives people who see this question an answer as well.
I normally do so when I don't have time or the resources to answer a question but have an idea on what the answer might be.
However, is this the correct approach?