If you turn up to meet a girl that offers all services with out extras and you are clean, presentable and non offensive, then chances are you will get everything offered. However, I guess some girls may not be in the mood to do certain things on certain days for whatever reason.
It is always best to make sure that if you are really keen to do a certain activity, this is discussed prior to the exchange of money. not taking for granted that she is happy to do it with you. This can seem a little clinical, but normally with a bit of friendly chit chat at the start will resolve this.
One of my regulars, who quite specifically never offered OWO, did on one occasion, much to my delight. Now some things are better approached indirectly, especially if you know the person. Of course, it could be that she just didn't usually enjoy it and nothing to do with me and nothing I could influence. Or maybe she preferred not to take a risk on any smelly cocks so just pre-emoted things. Or it might be something that what I did or said might have a bearing on.
So next time we were discussing an appointment - our appointments were fairly few and far between - I discussed an elaborate and original role play with her that, from my knowledge of her likes and dislikes, was probably up her street as it were. I happened to throw in that I would be meeting her after the gym, so would not only be freshly scrubbed but would maybe be freshly chlorinated as well. I mentioned the unusual OWO and said how fab it was, but that although I enjoyed it I was under no impression that it was routinely included and was entirely up to her on any particular occasion.
I would generally receive OWO without asking at subsequent meetings. On one occasion she did rubber me up, but I felt this was not necessarily any lack of 'chlorination' but more an assertion that it was her choice and not to be an expected thing.
All very satisfactory actually. (The only reason I haven't mentioned her name is that she still states on her profile that it is 'not a service she offers.')