I think the Dutch clogs thing was an example to say how shoes differ. He could have said crocs or flip flops or anything else.
Regarding the other points. It just takes one person (the right person) or a group of people. Yes, the elite athlete market is going to be small compared to the mass market but that doesn't mean it is not there. There is money to be made, there is money in athletics (admittedly not a lot compared to some sports) and when national pride is at stake, well. The motivation is certainly there. I'm not saying a chemist themselves would necessarily come up with all of this, I suppose my line of thought is more that a nefarious coach or administrative body may go along the route of employing an expert to become creative in a lab and tbh it would be interesting work for a lot of people.
Do you think that SARMs are massively effective? I'm not so sure. Compared to other substances of the past.
I feel like even ringing a doorbell then waiting gives someone enough time to get up to high jinks if they were really determined. You get to set your whereabouts location, after all.
I do think a lot of people take these risks. It really pisses me off!