My DS is 20 months, I'm in the don't force camp because I'm as concerned about the relationship as I am about the teeth. We do quite well at the moment, with him going, "Ahh!" and me cleaning his teeth. Our strategies for not-so-good times have been him doing my teeth and me doing his; everybody cleaning their teeth conspicuously in front of him; games of "Ahh," or copying each other's faces with tooth brushing happening as part of that; fancy tooth brushes; tooth brushes as toys in the toybox; cleaning teddy/ baby doll's teeth. We do teeth in the bath and I sometimes have to ask repeatedly, with little intervals, if we can do teeth now. I phrase it in such a way that the question is more when rather than if we will do them.
In desperate times, I have put a bit of toothpaste on my finger and spread it on his teeth - I wiggle my finger in front of his mouth and he usually allows it. In fact, for months the tooth procedure for us all was toothpaste onto finger, spread it onto teeth, then brush, just to make it make sense for him and also because I understood that getting flouride onto his teeth was a good thing and he used to spit and refuse the toothbrush almost straight after he'd let it in. I'm totally with you on the can't force a toothbrush in there front, but he has always let us pop some toothpaste on his teeth with a finger. Needless to say, I feign almost indifference about the whole thing, to keep the emotional temperature down as much as possible.
Re 'getting flouride into' DC or anyone, it's not that you want it in them so much as it is you want it on their teeth then spat out, if possible (spitting games are surely irresistible to all children?). As I understand it, flouride is pretty bad for you if swallowed. I only mention it so no one thinks getting DC to drink toothpasty water is a good idea in desperate times.