The service given is very high caliber, but they are also sticklers for hygiene and cleanliness. Most have the attitude that if they didn't wash it for you, or see you wash it yourself, it matters not if you just came from showering from across the hall in the same apartment complex. If you find the thought of a Kgirl tongue giving you rimming enticing, it's more likely to happen if she KNOWS for sure that your ass is clean because SHE is the one who washed it. Same thing applies to BBBJ with many of the Kgirls. Kgirls generally require no upcharge for BBBJ or rimming. The sole determining factor is whether she is completely comfortable with your cleanliness level. If she detects by scent or physical evidence that you may have stopped at a gas station or fast food place to relieve yourself on the way there, you are not likely to get her most enthusiastic service unless you shower, especially in places you would like her to put her mouth or tongue.
With that said, I will add that being with a new provider for the first time is often awkward and time is wasted sitting around chatting to get comfortable before disrobing. In Kgirl-land, the shower comes first, and I will often insist with indies I see that I want a co-ed shower as soon as I get there. Very few will refuse if the booking depends on it. Co-ed showers are the absolute best ice-breaker there is when seeing a new provider for the first time, Kgirl or otherwise. You say it annoys you, but if you consider what you might be missing by not showering, maybe you should try it and see if there isn't a higher level of enthusiasm in pleasing you when you comply with their hygiene expectations.
To answer your question on where to find them, KC is hit and miss. Sometimes there are orgs operating there, but generally with not more than 2-3 girls at a time. It's worth a trip to LA or the SF Bay Area for a week, and the selection and choices will blow your mind. You may have to give a little more personal information to get screened, but once you develop references within a geographic area, you can parlay that into references to other orgs without handing over your personal info each time you try a new agency. Hope this helps or at least provides food for thought.
