I suppose the vet might know more than we do as animal care givers. I'm assuming he would not mention antibiotics unless there is infection and the most direct treatment is the best treatment for an animal suffering an infection. The fluid leaking from her might be more than normal gland fluid; it could be pus/blood from an infection. Pay the extra for having her properly treated, as it appears she is at a later stage, with the medical issue of infection. Have her properly treated now so it doesn't lead to the next stage which is more severe, more suffering and more costly. Expressing the glands if not done correct and expressing them too much can do more harm than good. A good brand of dog food where the dog will have a firm stool as opposed to soft, can help in the release of this gland fluid which is suppose to be a very small amount, normally, each time when defecating.
For those insisting on saving money and expressing the anal glands themselves, below is a link for dummies.
How to Empty Your Dog's Anal Sacs - For Dummies
Link with videos: About a Dogs Anal Glands/Gland Problems and Diet.
About a Dog's Anal Glands