This is a tough one...everyone has their own "formula" to deal with ears/congestion. I couple the ears/congestion thing because ear problems are frequently caused by congestion in the eustachian tubes. My ears are pretty sensitive. The objective is to keep congestion down, keep ears dry, keep ear canals from getting inflamed, and keep ear canals from getting infected. The advice that I've been given is as follows: 1) Once you are on the dive trip, NEVER use Q tips to clean your ears. Your ears will try to create a protective coating in the canal if you are in the water a lot so removing it could expose the ear canal to bacteria. Basically you are removing a protective coating. 2) Never use alcohol by itself without glycerin. Alcohol will dry out your ears but will also create irritation of the skin (which can lead to inflammation). 3) Vinegar can be useful to create an environment that bacteria don't like. 4) Focus on keeping your ears dry...this means that you should use drying drops as soon as you get back to the live aboard (or room if you are land based) and you should never sleep with ear plugs. 5) Don't use decongestant since you can get a reverse squeeze if it wears off during a dive. I follow #1 religiously...I used to use Q tips and I always had issues towards the end of the trip...I stopped doing that and it worked. I follow #2 and #4 religiously as well. I use ear drops with glycerin (called Swim-EAR in the US). I ignore # 5...I've tried to dive without decongestants and it doesn't work for me. I use 12 hour pseudoephedrine (e.g. Sudafed). I take it right before the first dive and I am usually good to go through 4 dives. I have not needed #3 after I followed #1, #2, #4, & #5!