These parties are no frills, but I've had some good times, also 1 or 2 fairly indifferent times.
They can be busy, girls can take frequent breaks, and not too surprisingly the girls are not as young or attractive as those places which charge 6 times the hourly rate.
If you want the girls to acknowledge you why not encourage them by starting a short conversation, learn their names etc. I'm not the worlds best pick up artist by a long long way, but maybe worth putting a bit of effort in before writing them off as mechanical and unfriendly.