My surgeon gave me something similar to this:

Except the hose was brownish red. You can find it on Amazon by searching for "douche syringe". (I can't put a direct link per forum rules.)
It says it's disposable and for anal use, but can be safely used multiple times for vaginal use ONLY since it's NOT being used anally.
Just draw the solution (I use 1 Tablespoon white distilled vinegar to 1 cup tap water) in the syringe (you can save unused until later) and lubricate the tip with a water-based lubricant, insert in the vagina and push the plunger flushing out your vagina. If the fluid comes out stinky or non-clear, you might need to repeat again, but I've never had to repeat it the same day.