Somewhat dissenting opinion: DO use the medicated goop. It burns only because the yeast infection has gotten bad enough to get the tissues seriously irritated, which means that you need treatment. The seven-day goop may be less irritating than the three-day, but the three-day stuff is strong and fast and it may be worth toughing it out.

When it's gotten really bad before I've had a chance to start treatment, I've been known to shower and get really cleaned up right before bed, squirt in the goop, and stuff a tampon in after it. This is NOT a good practice, generally speaking, but made it tolerable to use the goop the first night without intolerable burning, which let it work well enough to start clearing up the problem, so that after that I could skip the plug.

Just my advice, FWIW.