Almost everyone here is jumping to conclusions.
We can't tell you if this is a successful strategy for you because we don't have enough information. Other reasons you may be having difficulty finding a candidate include
- Location : maybe you have a poor talent pool in your city. We don't know
- Type and Term : Looks like part-time. Good luck finding any talent for a part-time position.
- Niche : Is it a niche industry? Are you looking for rare skills?
- Salary : Are you offering too little?
- Job Description : Maybe the rest of your job description is poor. We don't know.
- Competition : Maybe you're a smaller city with a talent vacuum for competition. If you're competing with bigger fish for developers, you can easily have a hard time finding talent.
You have 47 CVs left on your desk. If you want an answer to your question, take the time to read through those ignoring the 'sunshine' request. If you find some gems, then you have the answer to your question. If you find more and worse garbage, then you also have an answer to your question. I suspect the remainder of those applicants are probably no better than the ones you've already rejected. If you're desperate, though, it's probably worth at least having a look through the ones you rejected in the first round.
The effectiveness of the 'sunshine' technique is going to depend highly on the specific circumstances in your city and industry. We simply don't have enough information to tell you whether it's an effective strategy or not. You'll have to figure that out for yourself.
At very least I might use it to shortlist those compliant CVs for a deeper read, but I probably wouldn't ignore the rest for that single reason. No candidate is perfect and completely rejecting any candidate for a single shortcoming should only be done if it's a critical requirement that you can't live without. I'd think the sunshine technique could be a useful tool for you, but it probably isn't an effective, all-purpose, one-stop-shop of a talent filter.