Just post your answer immediately after you post the question. Like you say, phrase it as a request for comments to improve your solution. Your intentions are clear --- I wouldn't think you were trying to generate reputation. Besides, it's my prerogative to reward or punish your efforts. Alternatively, you could mark your answer as a community wiki if you are feeling charitable.
You can nownow do this automatically by ticking the “Answer your own question” checkbox when posting the question, provided you have more than 15 reputation.