Re: Smegma under foreskin problem
I'm sorry to step on anyone's toes here, but I do think you probably know what smegma is and where it is (better than we do). There actually is a somewhat common cause of 'invisible smegma' like this.
I think what you might be describing is a foreskin adhesion. Are you saying there's an area between your glans and foreskin that can get smegma trapped in it, but it's only open a little bit at the underside of your penis? (It's only open around the frenulum?) An occluded adhesion like this is practically impossible to clean inside, so it pretty much always gets smegma. So yes, that is smegma you're feeling under the foreskin in the occluded space of the foreskin adhesion.
The way to clean this (for now) is to force water in from the underside. Force water in at the bottom so that it goes around the penis behind the glans and comes out the other side. You pretty much need a small tube hooked to a faucet to do this. (I'd say don't use high pressure, but you'd probably gather that from the fact that it hurts like crazy. That's the most sensitive part of your penis behind there.)
They say an adhesion like this is a natural part of the development of all men, but in most cases they've already separated by adolescence (around 90% or so I believe). See the sticky thread on the Men's Health board Stretching To Fix Tight Foreskin (Phimosis). At the bottom of that thread are some instructions about stretching to correct adhesions. I know it can be really weird because it looks like continuous skin. It's not actually, if you just keep applying gentle tension to it once or twice a day, it will separate after a week or two. (Don't ever apply so much tension that it hurts. That's unnecessary and may cause injury!)
Oh and I should say, there are some cases where it may not be correctable with stretching, but in that case it won't break your penis to try to correct it, it just won't separate. (The only thing that could "break" your penis is if the frenulum is very short and tears from getting pulled back to far. This is not likely to be your problem, but it too is also correctable with regular gentle stretching--there are directions on the previously mentioned thread.)
I said it's natural, but I've read that it can also be a consequence of a common medical mistake. It can cause adhesions to have the foreskin 'forcibly retracted' before it's ready (sometimes it's not able to retract until further development). So when it's forced back (ripped open essentially), it damages parts so that when it's returned to normal position, the raw wounds heal together and then don't want to separate as easily.