As long as you have a kicker that can get the ball to bounce high on the 1st bounce & make sure it goes 10yrds..I would think the percentages would be fairly high to get the ball back..It all depends on if you have that kicker that can consistently do that..Now as far as not punting the ball..Do they not even punt the ball if it's 4th & goal & the ball is inside your own 5yrd line???..And I don't like the idea to on-sides kick or not punt the ball..Cause I think it sends a message to your D you HC has no faith in you, but, I can see schools start doing this..Cause high school, college football & now the NFL have been trending away from the importance of a strong D & moving towards these HUNH high scoring type crap football we see now days..
If it's part of your philosophy, I don't think it sends that message. There's multiple ways to look at it - 1) We're trying to get the ball back because we have no faith in the defense, or 2) Coach knows the defense can hold them, so he is free to take risks. If your players know that you are going to onside kick every time, then when it happens it's just part of your gameplan. It's when you move away from your plan and go for it or onside kick that it becomes demoralizing.
In a lot of ways, it kind of makes sense. Even if you do give up a short field, your opponent will be limited in their time of possession. In the same way we always say with the HUNH that if you don't get a first down you put your defense right back on the field - this almost guarantees that result every time they get the ball. Eventually you'll wear their defense down, and your defense will be pretty fresh. Think of it like this: you give up a long 80 yard drive, then turn around a lose an onside kick. Now your defense is back on the field, unlikely to have much better results - now there's ANOTHER onside kick to defend...