OK I'm back. Thanks for the info and opinions posted thus far.
I, too, had trouble finding any concrete information on the subject. I am familiar with the use of medication to sterilize / remove sex drive in humans (a friend is a nurse in a mental institution where such treatment is sometimes necessary for the safety of patients and staff) but have not explored the same in canines.
The situation is this:
I find myself in an "interesting" situation. My roommate went schizo basically, so I'm in the process of moving. All fine and well. Wrench in the tire is this: the friends whose basement apartment I'll be renting, have two dogs of their own. One a 6 month old female Weim (a pet store puppy - don't even get me started). These people are the type that aren't bad, just uneducated. In that one of the first things they said to me was "Hey, Slade's intact right? We should breed them!". *facepalm* I'm doing my best to be a support system and educate them gently, and have explained that if Slade ever were to sire a litter, it would be after his Ch., to an approved bitch, and within the contractual obligation I have to his breeders, etc.
Having said that, you know owners who don't find it in their spare time to learn more than "feed at least once a day" about the dogs in their care. They don't "get it". They think it's "OMG not fair that someone can tell you what to do with your dog RE: the contract", etc. My concern is this: although I know they would never overtly disregard my wishes, I don't trust them to adequately supervise the goings-on between the dogs when I'm not around and their bitch matures. Let alone to even UNDERSTAND the urgency of complete segregation when she's in heat. They would do what they thought was their best I'm sure, but they seriously lack the education.
Slade will be 2 in a couple of weeks. He's still intact, and although due to my illness, etc. hasn't been working towards his Ch. as of late, it's still something I want for him. So I'm not ready to have him neutered yet.
Chemical Castration is the first thing that came to mind for me RE: being absolutely ASSURED there will be no accidents, while not cutting off his show career. I know there would always be the option of vasectomy vs. neuter as well, for the purposes of being "entire" for showing, but of course then even the possibility of siring if the opportunity presented itself when he finishes, would be off the table. Not that that's entirely a big deal to me. Breeding has never been my intention - I just never shut the door on it entirely. Just figured it would be a bridge his breeders and I would cross together. This is all of course under the impression I believed chemical means could be discontinued and therefore restore fertility. I'm finding from answers above that appears not to be the case.
I don't really LIKE the idea of medicating him for any reason, but the ethical weight of having to live with being 50% responsible for an accidental litter I like even less. And to think a) I can ALWAYS be home with him to supervise, b) I can always have someone watch him for me when I'm NOT, or c) that they won't let him out of my apartment when he's crying to be with their 2, is neither realistic or fair.