Advice removing water stains on front curtains

Jack at Colorado River Blinds told me to use is Club Soda he called it a trade secret! My wife and I have used Club Soda on many things since with great success! Remove the curtains pour on the Club Soda, then scrub gently with a soft bristle brush, let the curtains dry out in the sun and they will look near new. Our curtains were as you described when Jack seen them he told us about the trade secret that they use! You won't be sorry! Good Luck