Where are your temps and RH at? At this stage, you are more limited in what you can do to treat PM because the flowers will take on the flavor of whatever you spray on them. I would probably stick with citric acid or potassium bicarbonate at this point-they work by throwing the PH that PM can survive in way out of range either too low (citric acid) or too high (bicarbonate.) A lower dose of citric acid will work for PM than if you were using it to treat spider mites-a lot of commercial PM products that use citric acid use a .05% dilution, so if you want to try that at the lower end of the effective range, you would add .5 grams (500 mg) per liter of water. Add a couple of drops of dishsoap to that to break the surface tension, and spray the plant thoroughly. If you need to go higher, you could start with 1 g per liter as well, but just know that this treatment could damage your pistils, especially at higher concentrations. If I were you, I would do it anyway-you don't want to smoke mildewy bud. Also, consider a post harvest bud wash with citric acid as well. You can buy it at walmart, some grocery stores/hardware stores, in the section with canning supplies. To avoid this problem in the future, get a dehumidifier and set it at 50% RH, and increase the air circulation within your tent. Be sure you have fans above and below the canopy moving air-every leaf on the plant should have slight movement from the breeze. Clean your tent from top to bottom after this grow cycle with citric acid as well-make it much stronger than you would use on the plant-I use 2 teaspoons per liter of water for cleaning. Consider a weekly IPM spray during the veg cycle of your future grows as well-neem oil, Southern Ag Garden Friendly Fungicide, yucca extract-these are all good things to use and alternate in your weekly sprays (during VEG only) in the future.